|The first thing I would recommend is to download the latest drivers from the video card mfg's website (make sure they are XP drivers) and install them. The most likely cause is the video driver, so that should fix it. |
Second, make sure that the game(s) you are playing are within the limits you your system/video card's capabilities (the newest drivers above should also give you the maximum capabilities also). Try another game or two to be sure.
Third, Check your memory, a bad RAM stick can definitely cause problems when stressed to the max as in a game, Use Memtest to test for problems. If you show a problem, rerun with one stick of RAM at a time to find the problem one, and replace.
You have to be a little bit crazy to keep you from going insane.