WixInstallPath environment variable

Doc/using/windows.rst

@@ -25,7 +25,7 @@ As specified in :pep:`11`, a Python release only supports a Windows platform
 while Microsoft considers the platform under extended support. This means that
 Python |version| supports Windows 10 and newer. If you require Windows 7
 support, please install Python 3.8. If you require Windows 8.1 support,
-please install Python 3.12.
+please install Python 3.13.
 
 There are a number of different installers available for Windows, each with
 certain benefits and downsides.

Tools/msi/README.txt

@@ -61,18 +61,20 @@ the initial download size by separating them into their own MSIs.
 Building the Installer
 ======================
 
-Before building the installer, download extra build dependencies using
-Tools\msi\get_externals.bat. (Note that this is in addition to the
+Before building the installer, download the extra build dependencies
+using Tools\msi\get_externals.bat. (Note that this is in addition to the
 similarly named file in PCbuild.)
 
-One of the dependencies used in builds is WiX, a toolset that lets developers
-create installers for Windows Installer, the Windows installation engine.
+One of the dependencies used in the build process is WiX, a toolset that
+allows developers to create installers for Windows Installer, the
+Windows installation engine. If you're not using the copy of WiX
+installed by Tools\msi\get_externals.bat, you'll need to set the
+"WixInstallPath" environment variable before building.
 
-Additionally, make sure "MSVC v14x - VS 20xx C++ ARM64/ARM64EC build tools" are
-selected under "Desktop Development with C++" in "Visual Studio installer",
-even if you are not building on ARM64. This is required because we have
-upgraded to WiX-3.14, which requires these tools for Python 3.10 and later
-versions.
+Additionally, ensure that "MSVC v14x - VS 20xx C++ ARM64/ARM64EC build tools"
+is selected under "Desktop Development with C++" in the "Visual Studio Installer",
+even if you're not building on ARM64. This is required because we've upgraded
+to WiX 3.14, which requires these tools for Python 3.10 and later versions.
 
 For testing, the installer should be built with the Tools/msi/build.bat
 script:

Tools/msi/wix.props

@@ -5,7 +5,6 @@
   <PropertyGroup>
     <WixInstallPath Condition="'$(WixInstallPath)' == '' and Exists('$(MSBuildThisFileDirectory)\Wix')">$(MSBuildThisFileDirectory)\Wix\</WixInstallPath>
     <WixInstallPath Condition="'$(WixInstallPath)' == '' and Exists('$(ExternalsDir)\windows-installer\wix-314')">$(ExternalsDir)\windows-installer\wix-314\</WixInstallPath>
-    <WixInstallPath Condition="'$(WixInstallPath)' == ''">$(Registry:HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows Installer XML\3.14@InstallRoot)</WixInstallPath>
     <WixTargetsPath>$(WixInstallPath)\Wix.targets</WixTargetsPath>
   </PropertyGroup>
 </Project>