Think you got your information from an idiot.
Just saying.
Windows XP does C just fine, it depends what the program was written to run in first.
USAF was designed for W95/98 - DOS based kernel.
Windows XP is based off the NT kernel, not DOS.
This means the command prompt isn't real DOS, it's just a Command Line Interface that resembles DOS.
In other words, a dual boot with Windows 98 is the solution.
BUT, you can't install Windows 98 after Windows XP is installed... they need to be installed in order of oldest to newest to work properly in a dual boot environment.
-SW