"Due to Microsoft's extensive support for backward compatibility, it is not only possible to execute Windows 1.0 binary programs on current versions of Windows to a large extent but also to recompile their source code into an equally functional "modern" application with just limited modifications"
I haven't touched windows in probably 15 years though so I can't speak for any of this. Funny, I was a Windows software developer for a decade and now I know nothing about it. I don't even know if the debug tools I used to use made the leap to 64 bit
There was an article a couple of years ago about taking binaries from either windows 1 or 2, changing a few bits of the header and it would run fine.
Edit: actually it's covered in the Wikipedia article https://en.m.wikipedia.org/wiki/Windows_1.0x
It's an old citation but here's the snippet:
"Due to Microsoft's extensive support for backward compatibility, it is not only possible to execute Windows 1.0 binary programs on current versions of Windows to a large extent but also to recompile their source code into an equally functional "modern" application with just limited modifications"
I haven't touched windows in probably 15 years though so I can't speak for any of this. Funny, I was a Windows software developer for a decade and now I know nothing about it. I don't even know if the debug tools I used to use made the leap to 64 bit