The macros _WIN32, _WIN64 and _M_X64 are defined by the compiler. The VS 2008 IDE doesn't know about (some) of the macros and can display wrong information. In my case a section #ifdef _WIN64 was grayed out although the platform was x64. I've added the macros to pyproject.vsprops and x64.vsprops.
I've also added a paragraph about the property files to the readme and fixed the order of pyupdate > pyinstrument.