I just had this issue trying to compile python from source on windows. The error message was: "The build tools for v143 (Platform Toolset = 'v143') cannot be found" for pyshellext.vcxproj

The problem was I didn't have ARM v143 tools installed.

setting -p x64 as an arg to PCBuild\built.bat or -x64 to tools\msi\build.bat may help, or install the ARM tools as a workaround.