diff --git a/platforms/Windows/Directory.Build.targets b/platforms/Windows/Directory.Build.targets
index eb8c333c..c9777857 100644
--- a/platforms/Windows/Directory.Build.targets
+++ b/platforms/Windows/Directory.Build.targets
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
-  <ItemGroup Condition="'$(MSBuildProjectName)' != 'shared'">
-    <ProjectReference Include="..\shared\shared.wixproj" />
+  <ItemGroup Condition="'$(MSBuildProjectName)' != 'shared' AND '$(MSBuildProjectName)' != 'runtimelib'">
+    <ProjectReference Include="$(MSBuildThisFileDirectory)shared\shared.wixproj" />
   </ItemGroup>
 
   <Import Project="WiXCodeSigning.targets" />
diff --git a/platforms/Windows/bld/bld.wxs b/platforms/Windows/bld/bld.wxs
index c607b5fd..5676c194 100644
--- a/platforms/Windows/bld/bld.wxs
+++ b/platforms/Windows/bld/bld.wxs
@@ -1,10 +1,10 @@
-<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:ui="http://wixtoolset.org/schemas/v4/wxs/ui">
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
   <Package
       Language="1033"
       Manufacturer="swift.org"
       Name="!(loc.Bld_ProductName)"
       UpgradeCode="7e95dc06-7f84-4e8e-a038-8304af0468fb"
-      Version="$(var.ProductVersion)"
+      Version="$(ProductVersion)"
       Scope="$(PackageScope)">
 
     <Media Id="1" Cabinet="bld.cab" EmbedCab="yes" />
@@ -28,20 +28,20 @@
     <ComponentGroup Id="binutils" Directory="_usr_bin">
       <!-- TODO(compnerd) can we use symbolic links to llvm-ar.exe instead? -->
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-dlltool.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-dlltool.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-lib.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-lib.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-ranlib.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-ranlib.exe" />
       </Component>
       <!-- TODO(compnerd) can we use symbolic links to llvm-objdump.exe instead? -->
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-readelf.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-readelf.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-strip.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-strip.exe" />
       </Component>
       <!--
         TODO(compnerd) we should symlink:
@@ -59,94 +59,94 @@
       -->
 
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\dsymutil.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\dsymutil.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-ar.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-ar.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-cov.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-cov.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-cvtres.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-cvtres.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-cxxfilt.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-cxxfilt.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-dwarfdump.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-dwarfdump.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-dwp.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-dwp.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-lipo.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-lipo.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-mt.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-mt.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-nm.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-nm.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-objcopy.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-objcopy.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-objdump.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-objdump.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-pdbutil.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-pdbutil.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-profdata.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-profdata.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-rc.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-rc.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-readobj.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-readobj.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-size.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-size.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-strings.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-strings.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-symbolizer.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-symbolizer.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\llvm-undname.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\llvm-undname.exe" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="lto">
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\LTO.dll" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\LTO.dll" />
       </Component>
 
       <Component Directory="_usr_lib">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\LTO.lib" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\LTO.lib" />
       </Component>
 
       <Component Directory="_usr_include_llvm_c">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\include\llvm-c\lto.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\include\llvm-c\lto.h" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="clang" Directory="_usr_bin">
       <!-- TODO(compnerd) can we use symbolic links to clang.exe instead? -->
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\clang-cl.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\clang-cl.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\clang-cpp.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\clang-cpp.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\clang++.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\clang++.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\clang.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\clang.exe" />
       </Component>
       <!--
         TODO(compnerd) we should include:
@@ -160,29 +160,29 @@
     <ComponentGroup Id="lld" Directory="_usr_bin">
       <!-- TODO(compnerd) can we use symbolic links to lld.exe instead? -->
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\ld.lld.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\ld.lld.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\ld64.lld.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\ld64.lld.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\lld-link.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\lld-link.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\wasm-ld.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\wasm-ld.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\lld.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\lld.exe" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="BlocksRuntime">
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\BlocksRuntime.dll" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\BlocksRuntime.dll" />
       </Component>
 
       <Component Directory="_usr_lib">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\BlocksRuntime.lib" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\BlocksRuntime.lib" />
       </Component>
 
       <!-- TODO(compnerd) should we install the block headers? -->
@@ -190,11 +190,11 @@
 
     <ComponentGroup Id="libdispatch">
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\dispatch.dll" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\dispatch.dll" />
       </Component>
 
       <Component Directory="_usr_lib">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\dispatch.lib" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\dispatch.lib" />
       </Component>
 
       <!-- TODO(compnerd) should we install the dispatch headers? -->
@@ -202,61 +202,61 @@
 
     <ComponentGroup Id="SwiftCxx" Directory="_usr_lib_swift_swiftToCxx">
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\swiftToCxx\_SwiftCxxInteroperability.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\swiftToCxx\_SwiftCxxInteroperability.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\swiftToCxx\_SwiftStdlibCxxOverlay.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\swiftToCxx\_SwiftStdlibCxxOverlay.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\swiftToCxx\experimental-interoperability-version.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\swiftToCxx\experimental-interoperability-version.json" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="SwiftDemangle">
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\swiftDemangle.dll" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\swiftDemangle.dll" />
       </Component>
       <Component Directory="_usr_lib">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swiftDemangle.lib" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swiftDemangle.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="SwiftFeatures" Directory="_usr_share_swift">
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\share\swift\features.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\share\swift\features.json" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="SwiftMigrator" Directory="_usr_lib_swift_migrator">
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\migrator\ios4.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\migrator\ios4.json" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\migrator\ios42.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\migrator\ios42.json" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\migrator\macos4.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\migrator\macos4.json" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\migrator\macos42.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\migrator\macos42.json" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\migrator\overlay4.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\migrator\overlay4.json" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\migrator\overlay42.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\migrator\overlay42.json" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\migrator\tvos4.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\migrator\tvos4.json" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\migrator\tvos42.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\migrator\tvos42.json" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\migrator\watchos4.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\migrator\watchos4.json" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\migrator\watchos42.json" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\migrator\watchos42.json" />
       </Component>
     </ComponentGroup>
 
@@ -268,58 +268,58 @@
 
       <!-- TODO(compnerd) can we use symbolic links to swift-frontend.exe instead? -->
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\swift-api-digester.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\swift-api-digester.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\swift-autolink-extract.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\swift-autolink-extract.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\swift-symbolgraph-extract.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\swift-symbolgraph-extract.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\swift-demangle.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\swift-demangle.exe" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\swift-frontend.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\swift-frontend.exe" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="argument_parser" Directory="_usr_bin">
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\ArgumentParser.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\ArgumentParser.dll" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="tools_support_core" Directory="_usr_bin">
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\TSCBasic.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\TSCBasic.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\TSCUtility.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\TSCUtility.dll" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="swift_driver" Directory="_usr_bin">
       <!-- TODO(compnerd) can we use symbolic links to swift.exe instead? -->
       <Component>
-        <File Name="swiftc.exe" Source="$(var.DEVTOOLS_ROOT)\usr\bin\swift-driver.exe" />
+        <File Name="swiftc.exe" Source="$(DEVTOOLS_ROOT)\usr\bin\swift-driver.exe" />
       </Component>
 
       <Component>
-        <File Name="swift.exe" Source="$(var.DEVTOOLS_ROOT)\usr\bin\swift-driver.exe" />
+        <File Name="swift.exe" Source="$(DEVTOOLS_ROOT)\usr\bin\swift-driver.exe" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\swift-help.exe" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\swift-help.exe" />
       </Component>
 
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\SwiftOptions.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\SwiftOptions.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\SwiftDriver.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\SwiftDriver.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\SwiftDriverExecution.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\SwiftDriverExecution.dll" />
       </Component>
     </ComponentGroup>
 
diff --git a/platforms/Windows/bundle/installer.wxs b/platforms/Windows/bundle/installer.wxs
index 11348d3b..38230b3a 100644
--- a/platforms/Windows/bundle/installer.wxs
+++ b/platforms/Windows/bundle/installer.wxs
@@ -1,7 +1,7 @@
 <Wix xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:bal="http://wixtoolset.org/schemas/v4/wxs/bal">
   <Bundle
     Name="!(loc.BundleName)"
-    Version="$(var.ProductVersion)"
+    Version="$(ProductVersion)"
     Manufacturer="swift.org"
     Compressed="$(IsBundleCompressed)"
     UpgradeCode="710F1827-DA4A-4BF4-BDCE-D5F2D7C0DEF2">
diff --git a/platforms/Windows/cli/cli.wxs b/platforms/Windows/cli/cli.wxs
index 7cd8929c..05e6a7f7 100644
--- a/platforms/Windows/cli/cli.wxs
+++ b/platforms/Windows/cli/cli.wxs
@@ -4,7 +4,7 @@
       Manufacturer="swift.org"
       Name="!(loc.Cli_ProductName)"
       UpgradeCode="87019842-3f3e-4227-b5c5-23a8ef72ad89"
-      Version="$(var.ProductVersion)"
+      Version="$(ProductVersion)"
       Scope="$(PackageScope)">
 
     <Media Id="1" Cabinet="cli.cab" EmbedCab="yes" />
@@ -25,155 +25,155 @@
 
     <ComponentGroup Id="clang" Directory="_usr_bin">
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\clang-format.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\clang-format.exe" />
       </Component>
 
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\clang-tidy.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\clang-tidy.exe" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="libclang" Directory="_usr_include_clang_c">
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\libclang.dll" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\libclang.dll" />
       </Component>
 
       <Component Directory="_usr_lib">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\libclang.lib" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\libclang.lib" />
       </Component>
 
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\include\clang-c\BuildSystem.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\include\clang-c\BuildSystem.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\include\clang-c\CXCompilationDatabase.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\include\clang-c\CXCompilationDatabase.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\include\clang-c\CXErrorCode.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\include\clang-c\CXErrorCode.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\include\clang-c\CXString.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\include\clang-c\CXString.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\include\clang-c\Documentation.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\include\clang-c\Documentation.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\include\clang-c\FatalErrorHandler.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\include\clang-c\FatalErrorHandler.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\include\clang-c\Index.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\include\clang-c\Index.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\include\clang-c\Platform.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\include\clang-c\Platform.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\include\clang-c\Refactor.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\include\clang-c\Refactor.h" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="IndexStore" Directory="_usr_include_indexstore">
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\libIndexStore.dll" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\libIndexStore.dll" />
       </Component>
 
       <Component Directory="_usr_lib">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\libIndexStore.lib" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\libIndexStore.lib" />
       </Component>
 
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\local\include\indexstore\indexstore.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\local\include\indexstore\indexstore.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\local\include\indexstore\IndexStoreCXX.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\local\include\indexstore\IndexStoreCXX.h" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="_InternalSwiftScan" Directory="_usr_include__InternalSwiftScan">
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\_InternalSwiftScan.dll" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\_InternalSwiftScan.dll" />
       </Component>
 
       <Component Directory="_usr_lib">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\windows\_InternalSwiftScan.lib" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\windows\_InternalSwiftScan.lib" />
       </Component>
 
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\_InternalSwiftScan\DependencyScan.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\_InternalSwiftScan\DependencyScan.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\_InternalSwiftScan\DependencyScanMacros.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\_InternalSwiftScan\DependencyScanMacros.h" />
       </Component>
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\swift\_InternalSwiftScan\module.modulemap" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\swift\_InternalSwiftScan\module.modulemap" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="collections" Directory="_usr_bin">
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\Collections.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\Collections.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\DequeModule.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\DequeModule.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\OrderedCollections.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\OrderedCollections.dll" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="llbuild" Directory="_usr_bin">
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\llbuildSwift.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\llbuildSwift.dll" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="system" Directory="_usr_bin">
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\SystemPackage.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\SystemPackage.dll" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="CompilerPluginSupport" Directory="_usr_lib_swift_pm_ManifestAPI">
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\CompilerPluginSupport.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\CompilerPluginSupport.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\CompilerPluginSupport.lib" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\CompilerPluginSupport.lib" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\CompilerPluginSupport.swiftdoc" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\CompilerPluginSupport.swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\CompilerPluginSupport.swiftmodule" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\CompilerPluginSupport.swiftmodule" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="PackageDescription" Directory="_usr_lib_swift_pm_ManifestAPI">
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\PackageDescription.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\PackageDescription.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\PackageDescription.lib" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\PackageDescription.lib" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\PackageDescription.swiftdoc" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\PackageDescription.swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\PackageDescription.swiftmodule" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\ManifestAPI\PackageDescription.swiftmodule" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="PackagePlugin" Directory="_usr_lib_swift_pm_PluginAPI">
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\PluginAPI\PackagePlugin.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\PluginAPI\PackagePlugin.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\PluginAPI\PackagePlugin.lib" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\PluginAPI\PackagePlugin.lib" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\PluginAPI\PackagePlugin.swiftdoc" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\PluginAPI\PackagePlugin.swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\lib\swift\pm\PluginAPI\PackagePlugin.swiftmodule" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\lib\swift\pm\PluginAPI\PackagePlugin.swiftmodule" />
       </Component>
     </ComponentGroup>
 
@@ -183,47 +183,47 @@
       <ComponentGroupRef Id="PackagePlugin" />
 
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\swift-build.exe" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\swift-build.exe" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\swift-package.exe" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\swift-package.exe" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\swift-run.exe" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\swift-run.exe" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\swift-test.exe" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\swift-test.exe" />
       </Component>
 
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\Basics.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\Basics.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\Build.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\Build.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\Commands.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\Commands.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\CoreCommands.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\CoreCommands.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\DriverSupport.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\DriverSupport.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\PackageGraph.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\PackageGraph.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\PackageLoading.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\PackageLoading.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\PackageModel.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\PackageModel.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\SPMBuildCore.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\SPMBuildCore.dll" />
       </Component>
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\Workspace.dll" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\Workspace.dll" />
       </Component>
 
       <!-- FIXME(compnerd) we should include the SPM import libraries -->
@@ -232,7 +232,7 @@
     <ComponentGroup Id="swift_format" Directory="Tools">
       <?if $(INCLUDE_SWIFT_FORMAT) == true ?>
         <Component Id="swift_format.exe" Directory="Tools">
-          <File Source="$(var.SWIFT_FORMAT_BUILD)\swift-format.exe" />
+          <File Source="$(SWIFT_FORMAT_BUILD)\swift-format.exe" />
         </Component>
 
         <ComponentRef Id="SystemToolsEnvironmentVariables" />
diff --git a/platforms/Windows/dbg/dbg.wxs b/platforms/Windows/dbg/dbg.wxs
index 633b3098..1c72beba 100644
--- a/platforms/Windows/dbg/dbg.wxs
+++ b/platforms/Windows/dbg/dbg.wxs
@@ -1,10 +1,10 @@
-<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:ui="http://wixtoolset.org/schemas/v4/wxs/ui">
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
   <Package
       Language="1033"
       Manufacturer="swift.org"
       Name="!(loc.Dbg_ProductName)"
       UpgradeCode="91d382af-1e92-44dc-a4ad-aee91c1b5160"
-      Version="$(var.ProductVersion)"
+      Version="$(ProductVersion)"
       Scope="$(PackageScope)">
 
     <Media Id="1" Cabinet="dbg.cab" EmbedCab="yes" />
@@ -23,86 +23,86 @@
 
     <ComponentGroup Id="lldb">
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\lldb.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\lldb.exe" />
       </Component>
 
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\liblldb.dll" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\liblldb.dll" />
       </Component>
 
       <Component Directory="_usr_lib">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\liblldb.lib" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\liblldb.lib" />
       </Component>
 
       <Component Directory="_usr_lib_site_packages_lldb">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\__init__.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\__init__.py" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\_lldb.pyd" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\_lldb.pyd" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\embedded_interpreter.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\embedded_interpreter.py" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\lldb-argdumper.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\lldb-argdumper.exe" />
       </Component>
 
       <Component Directory="_usr_lib_site_packages_lldb_formatters">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\Logger.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\Logger.py" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb_formatters">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\__init__.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\__init__.py" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb_formatters">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\attrib_fromdict.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\attrib_fromdict.py" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb_formatters">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\cache.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\cache.py" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb_formatters">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\metrics.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\metrics.py" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb_formatters">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\synth.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\synth.py" />
       </Component>
 
       <Component Directory="_usr_lib_site_packages_lldb_formatters_cpp">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\cpp\__init__.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\cpp\__init__.py" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb_formatters_cpp">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\cpp\gnu_libstdcpp.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\cpp\gnu_libstdcpp.py" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb_formatters_cpp">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\cpp\libcxx.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\formatters\cpp\libcxx.py" />
       </Component>
 
       <Component Directory="_usr_lib_site_packages_lldb_utils">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\utils\__init__.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\utils\__init__.py" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb_utils">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\utils\in_call_stack.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\utils\in_call_stack.py" />
       </Component>
       <Component Directory="_usr_lib_site_packages_lldb_utils">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\utils\symbolication.py" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\site-packages\lldb\utils\symbolication.py" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="lldb_server">
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\lldb-server.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\lldb-server.exe" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="swift_repl">
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\repl_swift.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\repl_swift.exe" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="swift_inspect" Directory="Tools">
       <?if $(INCLUDE_SWIFT_INSPECT) == true ?>
         <Component Id="swift_inspect.exe" Directory="Tools">
-          <File Source="$(var.SWIFT_INSPECT_BUILD)\swift-inspect.exe" />
+          <File Source="$(SWIFT_INSPECT_BUILD)\swift-inspect.exe" />
         </Component>
 
         <ComponentRef Id="SystemToolsEnvironmentVariables" />
diff --git a/platforms/Windows/ide/ide.wxs b/platforms/Windows/ide/ide.wxs
index 6240eaf5..a4f53e2d 100644
--- a/platforms/Windows/ide/ide.wxs
+++ b/platforms/Windows/ide/ide.wxs
@@ -1,10 +1,10 @@
-<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:ui="http://wixtoolset.org/schemas/v4/wxs/ui">
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
   <Package
       Language="1033"
       Manufacturer="swift.org"
       Name="!(loc.Ide_ProductName)"
       UpgradeCode="8dd91c86-d13d-490b-b06b-9522a9cf504c"
-      Version="$(var.ProductVersion)"
+      Version="$(ProductVersion)"
       Scope="$(PackageScope)">
 
     <Media Id="1" Cabinet="sdk.cab" EmbedCab="yes" />
@@ -16,33 +16,33 @@
 
     <ComponentGroup Id="clangd" Directory="_usr_bin">
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\clangd.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\clangd.exe" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="lldb" Directory="_usr_bin">
       <Component>
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\lldb-vscode.exe" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\lldb-vscode.exe" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="sourcekitd">
       <Component Directory="_usr_bin">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\bin\sourcekitdInProc.dll" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\bin\sourcekitdInProc.dll" />
       </Component>
 
       <Component Directory="_usr_lib">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\lib\sourcekitdInProc.lib" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\lib\sourcekitdInProc.lib" />
       </Component>
 
       <Component Directory="_usr_include_SourceKit">
-        <File Source="$(var.TOOLCHAIN_ROOT)\usr\include\SourceKit\sourcekitd.h" />
+        <File Source="$(TOOLCHAIN_ROOT)\usr\include\SourceKit\sourcekitd.h" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="lsp" Directory="_usr_bin">
       <Component>
-        <File Source="$(var.DEVTOOLS_ROOT)\usr\bin\sourcekit-lsp.exe" />
+        <File Source="$(DEVTOOLS_ROOT)\usr\bin\sourcekit-lsp.exe" />
       </Component>
     </ComponentGroup>
 
diff --git a/platforms/Windows/runtime/runtime.wxs b/platforms/Windows/runtime/runtime.wxs
deleted file mode 100644
index 40f3480d..00000000
--- a/platforms/Windows/runtime/runtime.wxs
+++ /dev/null
@@ -1,124 +0,0 @@
-<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:ui="http://wixtoolset.org/schemas/v4/wxs/ui">
-  <?include ../shared/config.wxi?>
-
-  <Package
-      Language="1033"
-      Manufacturer="swift.org"
-      Name="!(loc.Runtime_ProductName_$(var.ProcessorArchitecture))"
-      UpgradeCode="bea8c6dc-f73e-445b-9486-2333d1cf2886"
-      Version="$(var.ProductVersion)"
-      Scope="$(PackageScope)">
-
-    <Media Id="1" Cabinet="runtime.cab" EmbedCab="yes" />
-    <MajorUpgrade DowngradeErrorMessage="!(loc.DowngradeError)" />
-
-    <DirectoryRef Id="INSTALLDIR">
-      <Directory Name="Runtimes">
-        <Directory Name="$(var.ProductVersion)">
-          <Directory Name="usr">
-            <Directory Id="runtimes_usr_bin" Name="bin" />
-          </Directory>
-        </Directory>
-      </Directory>
-    </DirectoryRef>
-
-
-    <ComponentGroup Id="stdlib" Directory="runtimes_usr_bin">
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swift_Concurrency.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swift_Differentiation.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swiftDistributed.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swift_RegexParser.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swift_StringProcessing.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swiftCore.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swiftCxx.dll" />
-      </Component>
-
-      <!-- TODO(compnerd) should we distribute the undecoration library in the runtime?
-      <Component Directory="_usr_bin" Id="swiftDemangle.dll">
-        <File Id="swiftDemangle.dll" Source="$(var.SDK_ROOT)\bin\swiftDemangle.dll" />
-      </Component>
-      -->
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swiftCRT.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swiftRemoteMirror.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swiftSwiftOnoneSupport.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swiftWinSDK.dll" />
-      </Component>
-    </ComponentGroup>
-
-    <ComponentGroup Id="BlocksRuntime" Directory="runtimes_usr_bin">
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\BlocksRuntime.dll" />
-      </Component>
-    </ComponentGroup>
-
-    <ComponentGroup Id="libdispatch" Directory="runtimes_usr_bin">
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\dispatch.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\swiftDispatch.dll" />
-      </Component>
-    </ComponentGroup>
-
-    <ComponentGroup Id="Foundation" Directory="runtimes_usr_bin">
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\Foundation.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\FoundationNetworking.dll" />
-      </Component>
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\FoundationXML.dll" />
-      </Component>
-    </ComponentGroup>
-
-    <ComponentGroup Id="plutil" Directory="runtimes_usr_bin">
-      <Component>
-        <File Source="$(var.SDK_ROOT)\usr\bin\plutil.exe" />
-      </Component>
-    </ComponentGroup>
-
-    <ComponentGroup Id="EnvironmentVariables" Directory="INSTALLDIR">
-      <Component Id="SystemEnvironmentVariables" Condition="ALLUSERS=1" Guid="8681d813-eb32-46f9-8b1c-f622b38b5eaf">
-        <Environment Id="SystemPath" Action="set" Name="Path" Part="last" Permanent="no" System="yes" Value="[runtimes_usr_bin]" />
-      </Component>
-      <Component Id="UserEnvironmentVariables" Condition="NOT ALLUSERS=1" Guid="b83f6521-8708-4e2d-afef-076d8cdd7528">
-        <Environment Id="UserPath" Action="set" Name="Path" Part="last" Permanent="no" System="no" Value="[runtimes_usr_bin]" />
-      </Component>
-    </ComponentGroup>
-
-    <!-- Feature -->
-    <Feature Id="SwiftRuntime" AllowAbsent="no" Title="!(loc.Runtime_ProductName_$(var.ProcessorArchitecture))">
-      <ComponentGroupRef Id="stdlib" />
-      <ComponentGroupRef Id="BlocksRuntime" />
-      <ComponentGroupRef Id="libdispatch" />
-      <ComponentGroupRef Id="Foundation" />
-
-      <ComponentGroupRef Id="EnvironmentVariables" />
-    </Feature>
-
-    <Feature Id="SwiftUtilities" AllowAbsent="yes" Title="Extra Swift Utilities Windows ($(var.ProcessorArchitecture))">
-      <ComponentGroupRef Id="plutil" />
-    </Feature>
-  </Package>
-</Wix>
diff --git a/platforms/Windows/runtime/runtime.wixproj b/platforms/Windows/runtimelib/runtimelib.wixproj
similarity index 72%
rename from platforms/Windows/runtime/runtime.wixproj
rename to platforms/Windows/runtimelib/runtimelib.wixproj
index 89b2c05d..38562480 100644
--- a/platforms/Windows/runtime/runtime.wixproj
+++ b/platforms/Windows/runtimelib/runtimelib.wixproj
@@ -1,5 +1,8 @@
 <Project Sdk="WixToolset.Sdk/4.0.1">
   <PropertyGroup>
+    <OutputType>Library</OutputType>
+    <BindFiles>true</BindFiles>
+
     <DefineConstants>
       $(DefineConstants);
       SDK_ROOT=$(SDK_ROOT)
diff --git a/platforms/Windows/runtimelib/runtimelib.wxs b/platforms/Windows/runtimelib/runtimelib.wxs
new file mode 100644
index 00000000..c4813601
--- /dev/null
+++ b/platforms/Windows/runtimelib/runtimelib.wxs
@@ -0,0 +1,88 @@
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
+  <Fragment>
+    <Directory Id="RUNTIMEDIR" ComponentGuidGenerationSeed="5ACF10A7-6ACC-4649-8839-C8A5B8252B75" />
+
+    <ComponentGroup Id="stdlib" Directory="RUNTIMEDIR">
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swift_Concurrency.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swift_Differentiation.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swiftDistributed.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swift_RegexParser.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swift_StringProcessing.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swiftCore.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swiftCxx.dll" />
+      </Component>
+
+      <!-- TODO(compnerd) should we distribute the undecoration library in the runtime?
+      <Component Directory="_usr_bin" Id="swiftDemangle.dll">
+        <File Id="swiftDemangle.dll" Source="$(SDK_ROOT)\bin\swiftDemangle.dll" />
+      </Component>
+      -->
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swiftCRT.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swiftRemoteMirror.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swiftSwiftOnoneSupport.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swiftWinSDK.dll" />
+      </Component>
+    </ComponentGroup>
+
+    <ComponentGroup Id="BlocksRuntime" Directory="RUNTIMEDIR">
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\BlocksRuntime.dll" />
+      </Component>
+    </ComponentGroup>
+
+    <ComponentGroup Id="libdispatch" Directory="RUNTIMEDIR">
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\dispatch.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\swiftDispatch.dll" />
+      </Component>
+    </ComponentGroup>
+
+    <ComponentGroup Id="Foundation" Directory="RUNTIMEDIR">
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\Foundation.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\FoundationNetworking.dll" />
+      </Component>
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\FoundationXML.dll" />
+      </Component>
+    </ComponentGroup>
+
+    <ComponentGroup Id="plutil" Directory="RUNTIMEDIR">
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\bin\plutil.exe" />
+      </Component>
+    </ComponentGroup>
+
+    <ComponentGroup Id="swift_runtime">
+      <ComponentGroupRef Id="stdlib" />
+      <ComponentGroupRef Id="BlocksRuntime" />
+      <ComponentGroupRef Id="libdispatch" />
+      <ComponentGroupRef Id="Foundation" />
+      <ComponentGroupRef Id="plutil" />
+    </ComponentGroup>
+  </Fragment>
+</Wix>
diff --git a/platforms/Windows/runtimemsi/runtimemsi.wixproj b/platforms/Windows/runtimemsi/runtimemsi.wixproj
new file mode 100644
index 00000000..543c02cf
--- /dev/null
+++ b/platforms/Windows/runtimemsi/runtimemsi.wixproj
@@ -0,0 +1,9 @@
+<Project Sdk="WixToolset.Sdk/4.0.1">
+  <PropertyGroup>
+    <OutputName>runtime</OutputName>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\runtimelib\runtimelib.wixproj" />
+  </ItemGroup>
+</Project>
diff --git a/platforms/Windows/runtimemsi/runtimemsi.wxs b/platforms/Windows/runtimemsi/runtimemsi.wxs
new file mode 100644
index 00000000..e24038a1
--- /dev/null
+++ b/platforms/Windows/runtimemsi/runtimemsi.wxs
@@ -0,0 +1,39 @@
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
+  <Package
+      Language="1033"
+      Manufacturer="swift.org"
+      Name="!(loc.Runtime_ProductName_$(sys.BUILDARCH))"
+      UpgradeCode="bea8c6dc-f73e-445b-9486-2333d1cf2886"
+      Version="$(ProductVersion)"
+      Scope="$(PackageScope)">
+
+    <MediaTemplate CabinetTemplate="runtime{0}.cab" EmbedCab="yes" />
+    <MajorUpgrade DowngradeErrorMessage="!(loc.DowngradeError)" />
+
+    <DirectoryRef Id="INSTALLDIR">
+      <Directory Name="Runtimes">
+        <Directory Name="$(ProductVersion)">
+          <Directory Name="usr">
+            <Directory Id="runtimes_usr_bin" Name="bin" />
+          </Directory>
+        </Directory>
+      </Directory>
+    </DirectoryRef>
+
+    <SetDirectory Id="RUNTIMEDIR" Value="[runtimes_usr_bin]" Sequence="first" />
+
+    <ComponentGroup Id="EnvironmentVariables" Directory="RUNTIMEDIR">
+      <Component Id="SystemEnvironmentVariables" Condition="ALLUSERS=1" Guid="8681d813-eb32-46f9-8b1c-f622b38b5eaf">
+        <Environment Id="SystemPath" Action="set" Name="Path" Part="last" Permanent="no" System="yes" Value="[runtimes_usr_bin]" />
+      </Component>
+      <Component Id="UserEnvironmentVariables" Condition="NOT ALLUSERS=1" Guid="b83f6521-8708-4e2d-afef-076d8cdd7528">
+        <Environment Id="UserPath" Action="set" Name="Path" Part="last" Permanent="no" System="no" Value="[runtimes_usr_bin]" />
+      </Component>
+    </ComponentGroup>
+
+    <Feature Id="SwiftRuntime" AllowAbsent="no" Title="!(loc.Runtime_ProductName_$(sys.BUILDARCH))">
+      <ComponentGroupRef Id="swift_runtime" />
+      <ComponentGroupRef Id="EnvironmentVariables" />
+    </Feature>
+  </Package>
+</Wix>
diff --git a/platforms/Windows/runtimemsm/runtimemsm.wixproj b/platforms/Windows/runtimemsm/runtimemsm.wixproj
new file mode 100644
index 00000000..a0e34686
--- /dev/null
+++ b/platforms/Windows/runtimemsm/runtimemsm.wixproj
@@ -0,0 +1,10 @@
+<Project Sdk="WixToolset.Sdk/4.0.1">
+  <PropertyGroup>
+    <OutputType>Module</OutputType>
+    <OutputName>runtime.$(ProductArchitecture)</OutputName>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\runtimelib\runtimelib.wixproj" />
+  </ItemGroup>
+</Project>
diff --git a/platforms/Windows/runtimemsm/runtimemsm.wxs b/platforms/Windows/runtimemsm/runtimemsm.wxs
new file mode 100644
index 00000000..4f1c13fa
--- /dev/null
+++ b/platforms/Windows/runtimemsm/runtimemsm.wxs
@@ -0,0 +1,19 @@
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
+
+  <?if $(sys.BUILDARCH) == x86 ?>
+    <?define ModuleId = "7CE7029A-912E-4BC3-BAEC-D17D6F44A879" ?>
+  <?elseif $(sys.BUILDARCH) == x64 ?>
+    <?define ModuleId = "DB845E25-FB6D-4DD3-A068-C6B17D561505" ?>
+  <?elseif $(sys.BUILDARCH) == arm64 ?>
+    <?define ModuleId = "8C012B90-1F1B-4CB2-858A-DD0BCE4A7B22" ?>
+  <?endif?>
+
+  <Module
+    Guid="$(ModuleId)"
+    Id="swift_runtime"
+    Language="0"
+    Version="$(ProductVersion)">
+
+    <ComponentGroupRef Id="swift_runtime" />
+  </Module>
+</Wix>
diff --git a/platforms/Windows/samples/HelloMergeModule/hello.exe b/platforms/Windows/samples/HelloMergeModule/hello.exe
new file mode 100644
index 00000000..34fa228e
Binary files /dev/null and b/platforms/Windows/samples/HelloMergeModule/hello.exe differ
diff --git a/platforms/Windows/samples/HelloMergeModule/hello.swift b/platforms/Windows/samples/HelloMergeModule/hello.swift
new file mode 100644
index 00000000..a0c53605
--- /dev/null
+++ b/platforms/Windows/samples/HelloMergeModule/hello.swift
@@ -0,0 +1 @@
+print("Hello World, from an installer built with a shiny new merge module!")
diff --git a/platforms/Windows/samples/HelloMergeModule/hellomm.wixproj b/platforms/Windows/samples/HelloMergeModule/hellomm.wixproj
new file mode 100644
index 00000000..57b4ddca
--- /dev/null
+++ b/platforms/Windows/samples/HelloMergeModule/hellomm.wixproj
@@ -0,0 +1,11 @@
+<Project Sdk="WixToolset.Sdk/4.0.1">
+  <PropertyGroup>
+    <DefineConstants>
+      $(DefineConstants);
+    </DefineConstants>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\runtimemsm\runtimemsm.wixproj" BindName="rtmsm" />
+  </ItemGroup>
+</Project>
diff --git a/platforms/Windows/samples/HelloMergeModule/hellomm.wxs b/platforms/Windows/samples/HelloMergeModule/hellomm.wxs
new file mode 100644
index 00000000..e9d8ffb2
--- /dev/null
+++ b/platforms/Windows/samples/HelloMergeModule/hellomm.wxs
@@ -0,0 +1,26 @@
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
+  <Package
+      Language="1033"
+      Manufacturer="swift.org"
+      Name="Hello Merge Module World"
+      UpgradeCode="C0050D86-A62E-41CD-844D-DF3501C4B5F1"
+      Version="1.0"
+      Scope="perUserOrMachine">
+
+    <MajorUpgrade DowngradeErrorMessage="A newer version of [ProductName] is already installed." />
+
+    <StandardDirectory Id="ProgramFiles6432Folder">
+      <Directory Id="INSTALLFOLDER" Name="!(bind.property.ProductName)">
+        <Merge Id="swift_runtime" Language="0" SourceFile="$(runtimemsm.TargetPath)" />
+      </Directory>
+    </StandardDirectory>
+
+    <Feature Id="Hello" AllowAbsent="no" Title="!(bind.property.ProductName)">
+      <MergeRef Id="swift_runtime" />
+
+      <Component Directory="INSTALLFOLDER">
+        <File Source="hello.exe" />
+      </Component>
+    </Feature>
+  </Package>
+</Wix>
diff --git a/platforms/Windows/sdk/sdk.wixproj b/platforms/Windows/sdk/sdk.wixproj
index 3b664580..4cc5cfa1 100644
--- a/platforms/Windows/sdk/sdk.wixproj
+++ b/platforms/Windows/sdk/sdk.wixproj
@@ -12,6 +12,12 @@
     <PackageReference Include="WixToolset.Heat" Version="4.0.1" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\runtimemsm\runtimemsm.wixproj" Properties="ProductArchitecture=x86" BindName="rtmsm.x86" />
+    <ProjectReference Include="..\runtimemsm\runtimemsm.wixproj" Properties="ProductArchitecture=amd64" BindName="rtmsm.amd64" />
+    <ProjectReference Include="..\runtimemsm\runtimemsm.wixproj" Properties="ProductArchitecture=arm64" BindName="rtmsm.arm64" />
+  </ItemGroup>
+
   <ItemGroup>
     <HarvestDirectory Include="$(SDK_ROOT)\usr\lib\swift\shims">
       <ComponentGroupName>SwiftShims</ComponentGroupName>
diff --git a/platforms/Windows/sdk/sdk.wxs b/platforms/Windows/sdk/sdk.wxs
index 8924a839..1d8b00d4 100644
--- a/platforms/Windows/sdk/sdk.wxs
+++ b/platforms/Windows/sdk/sdk.wxs
@@ -1,20 +1,19 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:ui="http://wixtoolset.org/schemas/v4/wxs/ui">
-  <?include ../shared/config.wxi?>
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
 
-  <?if $(var.ProductArchitecture) = "amd64"?>
+  <?if $(sys.BUILDARCH) = "x64"?>
     <?define ArchBinDir = "bin64"?>
     <?define ArchArchDir = "x86_64"?>
     <?define ArchTriple = "x86_64-unknown-windows-msvc"?>
-  <?elseif $(var.ProductArchitecture) = "arm64"?>
+  <?elseif $(sys.BUILDARCH) = "arm64"?>
     <?define ArchBinDir = "bin64a"?>
     <?define ArchArchDir = "aarch64"?>
     <?define ArchTriple = "aarch64-unknown-windows-msvc"?>
-  <?elseif $(var.ProductArchitecture) = "arm"?>
+  <?elseif $(sys.BUILDARCH) = "arm"?>
     <?define ArchBinDir = "bin32a"?>
     <?define ArchArchDir = "armv7"?>
     <?define ArchTriple = "armv7-unknown-windows-msvc"?>
-  <?elseif $(var.ProductArchitecture) = "x86"?>
+  <?elseif $(sys.BUILDARCH) = "x86"?>
     <?define ArchBinDir = "bin32"?>
     <?define ArchArchDir = "i686"?>
     <?define ArchTriple = "i686-unknown-windows-msvc"?>
@@ -23,9 +22,9 @@
   <Package
       Language="1033"
       Manufacturer="swift.org"
-      Name="!(loc.Sdk_ProductName_$(var.ProcessorArchitecture))"
+      Name="!(loc.Sdk_ProductName_$(sys.BUILDARCH))"
       UpgradeCode="4c37a396-d9e2-490a-89b7-0a3d271d847f"
-      Version="$(var.ProductVersion)"
+      Version="$(ProductVersion)"
       Scope="$(PackageScope)">
 
     <Media Id="1" Cabinet="sdk.cab" EmbedCab="yes" />
@@ -55,11 +54,11 @@
             -->
             <Directory Name="XCTest-development">
               <Directory Name="usr">
-                <Directory Id="XCTest_usr_bin" Name="$(var.ArchBinDir)"></Directory>
+                <Directory Id="XCTest_usr_bin" Name="$(ArchBinDir)" />
                 <Directory Name="lib">
                   <Directory Name="swift">
                     <Directory Name="windows">
-                      <Directory Id="XCTest_usr_lib_swift_windows_ARCH" Name="$(var.ArchArchDir)" />
+                      <Directory Id="XCTest_usr_lib_swift_windows_ARCH" Name="$(ArchArchDir)" />
                       <Directory Id="XCTest.swiftmodule" Name="XCTest.swiftmodule" />
                     </Directory>
                   </Directory>
@@ -97,7 +96,7 @@
                       <Directory Id="Swift.swiftmodule" Name="Swift.swiftmodule" />
                       <Directory Id="SwiftOnoneSupport.swiftmodule" Name="SwiftOnoneSupport.swiftmodule" />
                       <Directory Id="WinSDK.swiftmodule" Name="WinSDK.swiftmodule" />
-                      <Directory Id="WindowsSDK_usr_lib_swift_windows_ARCH" Name="$(var.ArchArchDir)" />
+                      <Directory Id="WindowsSDK_usr_lib_swift_windows_ARCH" Name="$(ArchArchDir)" />
                     </Directory>
                   </Directory>
                 </Directory>
@@ -111,345 +110,357 @@
 
     <ComponentGroup Id="XCTest">
       <Component Directory="XCTest_usr_bin">
-        <File Source="$(var.PLATFORM_ROOT)\Developer\Library\XCTest-development\usr\bin\XCTest.dll" />
+        <File Source="$(PLATFORM_ROOT)\Developer\Library\XCTest-development\usr\bin\XCTest.dll" />
       </Component>
       <Component Directory="XCTest_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.PLATFORM_ROOT)\Developer\Library\XCTest-development\usr\lib\swift\windows\XCTest.lib" />
+        <File Source="$(PLATFORM_ROOT)\Developer\Library\XCTest-development\usr\lib\swift\windows\XCTest.lib" />
       </Component>
       <Component Directory="XCTest.swiftmodule">
-        <File Name="$(var.ArchTriple).swiftdoc" Source="$(var.PLATFORM_ROOT)\Developer\Library\XCTest-development\usr\lib\swift\windows\$(var.ArchArchDir)\XCTest.swiftdoc" />
+        <File Name="$(ArchTriple).swiftdoc" Source="$(PLATFORM_ROOT)\Developer\Library\XCTest-development\usr\lib\swift\windows\$(ArchArchDir)\XCTest.swiftdoc" />
       </Component>
       <Component Directory="XCTest.swiftmodule">
-        <File Name="$(var.ArchTriple).swiftmodule" Source="$(var.PLATFORM_ROOT)\Developer\Library\XCTest-development\usr\lib\swift\windows\$(var.ArchArchDir)\XCTest.swiftmodule" />
+        <File Name="$(ArchTriple).swiftmodule" Source="$(PLATFORM_ROOT)\Developer\Library\XCTest-development\usr\lib\swift\windows\$(ArchArchDir)\XCTest.swiftmodule" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="SwiftRemoteMirror" Directory="WindowsSDK_usr_include_swift_SwiftRemoteMirror">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\include\swift\SwiftRemoteMirror\MemoryReaderInterface.h" />
+        <File Source="$(SDK_ROOT)\usr\include\swift\SwiftRemoteMirror\MemoryReaderInterface.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\include\swift\SwiftRemoteMirror\Platform.h" />
+        <File Source="$(SDK_ROOT)\usr\include\swift\SwiftRemoteMirror\Platform.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\include\swift\SwiftRemoteMirror\SwiftRemoteMirror.h" />
+        <File Source="$(SDK_ROOT)\usr\include\swift\SwiftRemoteMirror\SwiftRemoteMirror.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\include\swift\SwiftRemoteMirror\SwiftRemoteMirrorTypes.h" />
+        <File Source="$(SDK_ROOT)\usr\include\swift\SwiftRemoteMirror\SwiftRemoteMirrorTypes.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\include\swift\SwiftRemoteMirror\module.modulemap" />
+        <File Source="$(SDK_ROOT)\usr\include\swift\SwiftRemoteMirror\module.modulemap" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swiftRemoteMirror.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swiftRemoteMirror.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="BlocksRuntime">
       <Component Directory="WindowsSDK_usr_include_Block">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\Block\Block.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\Block\Block.h" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\BlocksRuntime.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\BlocksRuntime.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="libdispatch" Directory="WindowsSDK_usr_include_dispatch">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\base.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\base.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\block.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\block.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\data.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\data.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\dispatch.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\dispatch.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\group.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\group.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\introspection.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\introspection.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\io.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\io.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\module.modulemap" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\module.modulemap" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\object.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\object.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\once.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\once.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\queue.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\queue.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\semaphore.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\semaphore.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\source.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\source.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\dispatch\time.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\dispatch\time.h" />
       </Component>
       <Component Directory="WindowsSDK_usr_include_os">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\os\generic_base.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\os\generic_base.h" />
       </Component>
       <Component Directory="WindowsSDK_usr_include_os">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\os\generic_unix_base.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\os\generic_unix_base.h" />
       </Component>
       <Component Directory="WindowsSDK_usr_include_os">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\os\generic_win_base.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\os\generic_win_base.h" />
       </Component>
       <Component Directory="WindowsSDK_usr_include_os">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\os\object.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\os\object.h" />
       </Component>
       <Component Directory="Dispatch.swiftmodule">
-        <File Name="$(var.ArchTriple).swiftdoc" Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\Dispatch.swiftdoc" />
+        <File Name="$(ArchTriple).swiftdoc" Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\Dispatch.swiftdoc" />
       </Component>
       <Component Directory="Dispatch.swiftmodule">
-        <File Name="$(var.ArchTriple).swiftmodule" Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\Dispatch.swiftmodule" />
+        <File Name="$(ArchTriple).swiftmodule" Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\Dispatch.swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\dispatch.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\dispatch.lib" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\swiftDispatch.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\swiftDispatch.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="_Concurrency" Directory="_Concurrency.swiftmodule">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_Concurrency.swiftmodule\$(var.ArchTriple).swiftdoc" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_Concurrency.swiftmodule\$(ArchTriple).swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_Concurrency.swiftmodule\$(var.ArchTriple).swiftinterface" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_Concurrency.swiftmodule\$(ArchTriple).swiftinterface" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_Concurrency.swiftmodule\$(var.ArchTriple).swiftmodule" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_Concurrency.swiftmodule\$(ArchTriple).swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swift_Concurrency.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swift_Concurrency.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="_Differentiation" Directory="_Differentiation.swiftmodule">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_Differentiation.swiftmodule\$(var.ArchTriple).swiftdoc" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_Differentiation.swiftmodule\$(ArchTriple).swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_Differentiation.swiftmodule\$(var.ArchTriple).swiftinterface" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_Differentiation.swiftmodule\$(ArchTriple).swiftinterface" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_Differentiation.swiftmodule\$(var.ArchTriple).swiftmodule" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_Differentiation.swiftmodule\$(ArchTriple).swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swift_Differentiation.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swift_Differentiation.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="_RegexParser" Directory="_RegexParser.swiftmodule">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_RegexParser.swiftmodule\$(var.ArchTriple).swiftdoc" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_RegexParser.swiftmodule\$(ArchTriple).swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_RegexParser.swiftmodule\$(var.ArchTriple).swiftinterface" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_RegexParser.swiftmodule\$(ArchTriple).swiftinterface" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_RegexParser.swiftmodule\$(var.ArchTriple).swiftmodule" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_RegexParser.swiftmodule\$(ArchTriple).swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swift_RegexParser.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swift_RegexParser.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="_StringProcessing" Directory="_StringProcessing.swiftmodule">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_StringProcessing.swiftmodule\$(var.ArchTriple).swiftdoc" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_StringProcessing.swiftmodule\$(ArchTriple).swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_StringProcessing.swiftmodule\$(var.ArchTriple).swiftinterface" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_StringProcessing.swiftmodule\$(ArchTriple).swiftinterface" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\_StringProcessing.swiftmodule\$(var.ArchTriple).swiftmodule" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\_StringProcessing.swiftmodule\$(ArchTriple).swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swift_StringProcessing.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swift_StringProcessing.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="CRT" Directory="CRT.swiftmodule">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\CRT.swiftmodule\$(var.ArchTriple).swiftdoc" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\CRT.swiftmodule\$(ArchTriple).swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\CRT.swiftmodule\$(var.ArchTriple).swiftinterface" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\CRT.swiftmodule\$(ArchTriple).swiftinterface" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\CRT.swiftmodule\$(var.ArchTriple).swiftmodule" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\CRT.swiftmodule\$(ArchTriple).swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swiftCRT.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swiftCRT.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="Cxx" Directory="Cxx.swiftmodule">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\Cxx.swiftmodule\$(var.ArchTriple).swiftdoc" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\Cxx.swiftmodule\$(ArchTriple).swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\Cxx.swiftmodule\$(var.ArchTriple).swiftinterface" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\Cxx.swiftmodule\$(ArchTriple).swiftinterface" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\Cxx.swiftmodule\$(var.ArchTriple).swiftmodule" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\Cxx.swiftmodule\$(ArchTriple).swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swiftCxx.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swiftCxx.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="Distributed" Directory="Distributed.swiftmodule">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\Distributed.swiftmodule\$(var.ArchTriple).swiftdoc" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\Distributed.swiftmodule\$(ArchTriple).swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\Distributed.swiftmodule\$(var.ArchTriple).swiftinterface" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\Distributed.swiftmodule\$(ArchTriple).swiftinterface" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\Distributed.swiftmodule\$(var.ArchTriple).swiftmodule" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\Distributed.swiftmodule\$(ArchTriple).swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swiftDistributed.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swiftDistributed.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="Foundation" Directory="Foundation.swiftmodule">
       <Component>
-        <File Name="$(var.ArchTriple).swiftdoc" Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\Foundation.swiftdoc" />
+        <File Name="$(ArchTriple).swiftdoc" Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\Foundation.swiftdoc" />
       </Component>
       <Component>
-        <File Name="$(var.ArchTriple).swiftmodule" Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\Foundation.swiftmodule" />
+        <File Name="$(ArchTriple).swiftmodule" Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\Foundation.swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\Foundation.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\Foundation.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="FoundationNetworking" Directory="FoundationNetworking.swiftmodule">
       <Component>
-        <File Name="$(var.ArchTriple).swiftdoc" Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\FoundationNetworking.swiftdoc" />
+        <File Name="$(ArchTriple).swiftdoc" Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\FoundationNetworking.swiftdoc" />
       </Component>
       <Component>
-        <File Name="$(var.ArchTriple).swiftmodule" Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\FoundationNetworking.swiftmodule" />
+        <File Name="$(ArchTriple).swiftmodule" Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\FoundationNetworking.swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\FoundationNetworking.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\FoundationNetworking.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="FoundationXML" Directory="FoundationXML.swiftmodule">
       <Component>
-        <File Name="$(var.ArchTriple).swiftdoc" Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\FoundationXML.swiftdoc" />
+        <File Name="$(ArchTriple).swiftdoc" Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\FoundationXML.swiftdoc" />
       </Component>
       <Component>
-        <File Name="$(var.ArchTriple).swiftmodule" Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\FoundationXML.swiftmodule" />
+        <File Name="$(ArchTriple).swiftmodule" Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\FoundationXML.swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\FoundationXML.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\FoundationXML.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="Swift" Directory="Swift.swiftmodule">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\Swift.swiftmodule\$(var.ArchTriple).swiftdoc" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\Swift.swiftmodule\$(ArchTriple).swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\Swift.swiftmodule\$(var.ArchTriple).swiftinterface" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\Swift.swiftmodule\$(ArchTriple).swiftinterface" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\Swift.swiftmodule\$(var.ArchTriple).swiftmodule" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\Swift.swiftmodule\$(ArchTriple).swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swiftCore.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swiftCore.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="SwiftOnoneSupport" Directory="SwiftOnoneSupport.swiftmodule">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\SwiftOnoneSupport.swiftmodule\$(var.ArchTriple).swiftdoc" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\SwiftOnoneSupport.swiftmodule\$(ArchTriple).swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\SwiftOnoneSupport.swiftmodule\$(var.ArchTriple).swiftinterface" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\SwiftOnoneSupport.swiftmodule\$(ArchTriple).swiftinterface" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\SwiftOnoneSupport.swiftmodule\$(var.ArchTriple).swiftmodule" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\SwiftOnoneSupport.swiftmodule\$(ArchTriple).swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swiftSwiftOnoneSupport.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swiftSwiftOnoneSupport.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="WinSDK" Directory="WinSDK.swiftmodule">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\WinSDK.swiftmodule\$(var.ArchTriple).swiftdoc" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\WinSDK.swiftmodule\$(ArchTriple).swiftdoc" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\WinSDK.swiftmodule\$(var.ArchTriple).swiftinterface" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\WinSDK.swiftmodule\$(ArchTriple).swiftinterface" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\WinSDK.swiftmodule\$(var.ArchTriple).swiftmodule" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\WinSDK.swiftmodule\$(ArchTriple).swiftmodule" />
       </Component>
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swiftWinSDK.lib" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swiftWinSDK.lib" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="libcxxshim" Directory="WindowsSDK_usr_lib_swift_windows">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\libcxxshim.h" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\libcxxshim.h" />
       </Component>
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\libcxxshim.modulemap" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\libcxxshim.modulemap" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="Registrar" Directory="WindowsSDK_usr_lib_swift_windows_ARCH">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swiftrt.obj" />
+        <File Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swiftrt.obj" />
       </Component>
       <!--
       <Component Directory="WindowsSDK_usr_lib_swift_windows_ARCH" Id="swiftrtd.obj">
-        <File Id="swiftrtd.obj" Source="$(var.SDK_ROOT)\usr\lib\swift\windows\$(var.ArchArchDir)\swiftrtd.obj" />
+        <File Id="swiftrtd.obj" Source="$(SDK_ROOT)\usr\lib\swift\windows\$(ArchArchDir)\swiftrtd.obj" />
       </Component>
       -->
     </ComponentGroup>
 
     <ComponentGroup Id="AuxiliaryFiles" Directory="WindowsSDK_usr_share">
       <Component>
-        <File Source="$(var.SDK_ROOT)\usr\share\ucrt.modulemap" />
+        <File Source="$(SDK_ROOT)\usr\share\ucrt.modulemap" />
       </Component>
-      <Component Directory="WindowsSDK_usr_share">
-        <File Source="$(var.SDK_ROOT)\usr\share\winsdk.modulemap" />
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\share\winsdk.modulemap" />
       </Component>
-      <Component Directory="WindowsSDK_usr_share">
-        <File Source="$(var.SDK_ROOT)\usr\share\vcruntime.apinotes" />
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\share\vcruntime.apinotes" />
       </Component>
-      <Component Directory="WindowsSDK_usr_share">
-        <File Source="$(var.SDK_ROOT)\usr\share\vcruntime.modulemap" />
+      <Component>
+        <File Source="$(SDK_ROOT)\usr\share\vcruntime.modulemap" />
       </Component>
     </ComponentGroup>
 
     <ComponentGroup Id="Configuration">
       <Component Directory="WindowsSDK">
-        <File Source="$(var.SDK_ROOT)\SDKSettings.plist" />
+        <File Source="$(SDK_ROOT)\SDKSettings.plist" />
       </Component>
       <Component Directory="WindowsPlatform">
-        <File Source="$(var.PLATFORM_ROOT)\Info.plist" />
+        <File Source="$(PLATFORM_ROOT)\Info.plist" />
+      </Component>
+    </ComponentGroup>
+
+    <ComponentGroup Id="RuntimeMergeModules" Directory="WindowsSDK_usr_share" Subdirectory="RuntimeMergeModules">
+      <Component>
+        <File Source="!(bindpath.rtmsm.x86)\runtime.x86.msm" />
+      </Component>
+      <Component>
+        <File Source="!(bindpath.rtmsm.amd64)\runtime.amd64.msm" />
+      </Component>
+      <Component>
+        <File Source="!(bindpath.rtmsm.arm64)\runtime.arm64.msm" />
       </Component>
     </ComponentGroup>
 
@@ -465,7 +476,7 @@
     </ComponentGroup>
 
     <!-- Features -->
-    <Feature Id="SDK" AllowAbsent="no" Title="!(loc.Sdk_ProductName_$(var.ProcessorArchitecture))">
+    <Feature Id="SDK" AllowAbsent="no" Title="!(loc.Sdk_ProductName_$(sys.BUILDARCH))">
       <ComponentGroupRef Id="XCTest" />
       <ComponentGroupRef Id="SwiftRemoteMirror" />
       <ComponentGroupRef Id="BlocksRuntime" />
@@ -488,6 +499,7 @@
       <ComponentGroupRef Id="AuxiliaryFiles" />
       <ComponentGroupRef Id="Configuration" />
       <ComponentGroupRef Id="SwiftShims" />
+      <ComponentGroupRef Id="RuntimeMergeModules" />
       <ComponentGroupRef Id="EnvironmentVariables" />
     </Feature>
   </Package>
diff --git a/platforms/Windows/shared/config.wxi b/platforms/Windows/shared/config.wxi
deleted file mode 100644
index edfea53a..00000000
--- a/platforms/Windows/shared/config.wxi
+++ /dev/null
@@ -1,13 +0,0 @@
-<?xml version='1.0' encoding='utf-8'?>
-
-<Include>
-<?if $(var.ProductArchitecture) = "amd64"?>
-  <?define ProcessorArchitecture = "AMD64"?>
-<?elseif $(var.ProductArchitecture) = "arm64"?>
-  <?define ProcessorArchitecture = "ARM64"?>
-<?elseif $(var.ProductArchitecture) = "arm"?>
-  <?define ProcessorArchitecture = "ARM"?>
-<?elseif $(var.ProductArchitecture) = "x86"?>
-  <?define ProcessorArchitecture = "x86"?>
-<?endif?>
-</Include>
diff --git a/platforms/Windows/shared/shared.wxs b/platforms/Windows/shared/shared.wxs
index 10f082ac..02ae9fd5 100644
--- a/platforms/Windows/shared/shared.wxs
+++ b/platforms/Windows/shared/shared.wxs
@@ -1,4 +1,4 @@
-<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:ui="http://wixtoolset.org/schemas/v4/wxs/ui">
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
   <Fragment>
     <StandardDirectory Id="ProgramFiles6432Folder">
       <Directory Id="INSTALLDIR" Name="Swift" />
@@ -8,7 +8,7 @@
   <Fragment>
     <DirectoryRef Id="INSTALLDIR">
         <Directory Name="Toolchains">
-          <Directory Name="$(var.ProductVersion)+Asserts">
+          <Directory Name="$(ProductVersion)+Asserts">
             <Directory Id="_usr" Name="usr">
               <Directory Id="_usr_bin" Name="bin" />
               <Directory Id="_usr_include" Name="include" />
diff --git a/platforms/Windows/shared/swift.en-us.wxl b/platforms/Windows/shared/swift.en-us.wxl
index e3b55e3a..2eece4a6 100644
--- a/platforms/Windows/shared/swift.en-us.wxl
+++ b/platforms/Windows/shared/swift.en-us.wxl
@@ -4,10 +4,10 @@
   <String Id="Cli_ProductName" Value="Swift Command Line Tools" />
   <String Id="Dbg_ProductName" Value="Swift Debugging Tools" />
   <String Id="Ide_ProductName" Value="Swift IDE Integration Tools" />
-  <String Id="Runtime_ProductName_AMD64" Value="Swift Utilities Windows (AMD64)" />
-  <String Id="Runtime_ProductName_ARM64" Value="Swift Utilities Windows (ARM64)" />
-  <String Id="Sdk_ProductName_AMD64" Value="Swift Windows SDK (AMD64)" />
-  <String Id="Sdk_ProductName_ARM64" Value="Swift Windows SDK (ARM64)" />
+  <String Id="Runtime_ProductName_x64" Value="Swift Utilities Windows (AMD64)" />
+  <String Id="Runtime_ProductName_arm64" Value="Swift Utilities Windows (ARM64)" />
+  <String Id="Sdk_ProductName_x64" Value="Swift Windows SDK (AMD64)" />
+  <String Id="Sdk_ProductName_arm64" Value="Swift Windows SDK (ARM64)" />
   <String Id="Sdk_ProductName_x86" Value="Swift Windows SDK (x86)" />
   <String Id="BundleName" Value="Swift Software Development Kit" />
 </WixLocalization>