diff --git a/INSTALL.md b/INSTALL.md
index 8e6791ef..621f7816 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -19,8 +19,31 @@ these versions.
 
 # Notes for Windows Users
 
-It seems that the default python on Windows is not fully functional,
-and windows might not allow executing python scripts by default.  See
+If you don't do a full blown Python web development on Windows the
+best way to install git-filter-repo is to use Python and pip from
+[Microsoft
+Store](https://docs.microsoft.com/en-us/windows/python/beginners).
+Follow these simple steps:
+
+1. Install Python from Microsoft Store.
+2. Run `pip install git-filter-repo` from the Windows Command Prompt.
+3. Copy git-filter-repo file from
+    *%LOCALAPPDATA%\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\Scripts*
+    to the directory pointed to by `git --exec-path`,
+
+    or
+
+    add
+    *%LOCALAPPDATA%\Packages\PythonSoftwareFoundation.Python.3.9_qbz5n2kfra8p0\LocalCache\local-packages\Python39\Scripts*
+    to you PATH environment variable.
+    
+    The folder above could be different depending on your Python's
+    version.
+
+If you have Python installed via
+[WSL](https://docs.microsoft.com/en-us/windows/python/web-frameworks)
+or from official [Python for Windows
+installer](https://www.python.org/downloads/windows/) see
 [issue 124](https://github.com/newren/git-filter-repo/issues/124),
 [issue 36](https://github.com/newren/git-filter-repo/issues/36), and
 [this git mailing list
diff --git a/git-filter-repo b/git-filter-repo
index 10401e45..ae03111b 100755
--- a/git-filter-repo
+++ b/git-filter-repo
@@ -1622,7 +1622,10 @@ class FilteringOptions(object):
       if suffix.startswith('rename'):
         mod_type = 'rename'
         match_type = option_string[len('--path-rename-'):] or 'match'
-        values = values.split(b':', 1)
+        values = values.split(b':')
+        if len(values) != 2:
+          raise SystemExit(_("Error: --path-rename expects one colon in its"
+                             " argument: <old_name:new_name>."))
         if values[0] and values[1] and not (
            values[0].endswith(b'/') == values[1].endswith(b'/')):
           raise SystemExit(_("Error: With --path-rename, if OLD_NAME and "
@@ -1862,7 +1865,7 @@ EXAMPLES
                "part of git history, historical versions of the file will "
                "be ignored; only the current contents are consulted."))
     people.add_argument('--use-mailmap', dest='mailmap',
-        action='store_const', const='.mailmap',
+        action='store_const', const=b'.mailmap',
         help=_("Same as: '--mailmap .mailmap' "))
 
     parents = parser.add_argument_group(title=_("Parent rewriting"))