This tip is really interesting because too many people don't know it. I know some of them who are angry to have to "rewrite" their applications in 32 or 64-bits ( but they were among the ... people who prefered Windows Millenium to Windows 2000 Pro only because of the presence of Pro ). I am hesitating to write an interesting tip or an useful tip ( the second one seems me to be better )

Its true that native Win64 does not support 16 bits apps, and that started with Windows xp64. But at leat under Windows 7 you can use the "Virtual XP mode" to run your 16bit apps. However, this is not supported on server systems and the smaller editions of Windows7...

I haven't seen a 16-bit application in at least 10 years. Is anyone out there still running 16-bit apps?

If written in a language like Visual Basic (VB 4.0 was the last version to support compiling 16-bit apps), the application will have to be re-written in a more modern language. It's possible to recompile using VB 5 or VB 6 (if you can find a copy) with minor changes. Note that VB 4.0 was released in 1995... 17 years ago.

If written in ANSI-compliant C, any 32-bit C compiler should work with minor changes.

This assumes you can locate the source code.