Blog post by Steve Dower of Microsoft and CPython core developer. '''How to deal with the pain of “unable to find vcvarsall.bat”''' https://blogs.msdn.microsoft.com/pythonengineering/2016/04/11/unable-to-find-vcvarsall-bat/ Explains the message and the two solutions: get the needed C compiler; get a precompiled binary. -- Terry Jan Reedy