If an effect is not supported, which it almost always will be, then it will silently fail. A computer with DirectX 8.1 and above should be able to handle all effects. A computer with DirectX 7.0 and above should at least be able to run the program without crashing. Performance will vary from machine to machine, but for most games, it shouldn't dip below 20 FPS, even without hardware acceleration. However, programs made in DarkBASIC cannot be made to work on anything older than Windows 95, no matter what. So, here are the minimum system reqs:
Windows 95 and above
DirectX 7.0 and above
The recommended:
Windows 98 and above
DirectX 8.1 and above
WINNER list:
Latch, Lee Bamber, TDK, TheComet
Thanks for the help!