I wondered the same and actually tried it on Windows 95 - it will be a bit more work. The bottom screen shots in this comment https://github.com/solvespace/solvespace/issues/1036#issueco... are the missing APIs on Win95...

I expect the build for Windows 2000 may work on NT 4.0, because it has OpenGL, but Windows 3.11 with Win32s will never work - because it does not have OpenGL(I think...).

And Unicode will also be a problem https://en.wikipedia.org/wiki/Unicode_in_Microsoft_Windows