7550 - You may be out of luck trying to get it to run under XP. Try the latest drivers as Richard suggested, and also look for a patch for the program from the publisher. Some games and flight sims were written with the expectation that they would be on Win95 or 98, which are very different under the hood and don't react well to XP. Unfortunately for many of these programs, there is little hope as the publishers or developers won't update them. If the program lists WindowsNT or 200 nder the requirements, then the problem is something else, but if it doesn't this probably what you are running into.
I have one computer at home that has both Win98 and WinXP Home on it, and some games will not run under XP, even with the latest drivers for the video card (an ATI 7500). The screen just turns black while the sound still works fine. Under 98 with the same driver version number (I used the latest Catalyst drivers for both 98 and XP) the games run great.
Good luck!
goates