[ithkuil]

I'm not doubting that the windows API has remained stable. I'd like to try if the tooling (e.g. IDE config format or makefile equivalent) has also received the same amount of attention to backward compat

[pjmlp]

Again, depends on what you were using.

Borland C++ or Watcom, probably not much help.

Delphi, C++ Builder, Visual C++ for Windows 95/2000 mostly work, naturally you might need to use the IDE wizards to upgrade project files, or fix tooling paths on the makefiles.