Game made 30 years ago needs dosbox, an open source project, to just work.

Game made with directx6 20 years ago will render in CPU and just work but be so slow to be unplayable. Then you need to replace the .dll and make it link with an open source library that reimplements dx and converts the calls to the new API, so that it can actually render in hardware.

Yes, solitaire.exe still works. 3d games less so.

I'm full of games like star wars jedi outcast or so that no longer work on windows.