Not sure if this will do the trick as I don't know anything about games, but it seems to me that the problem is games-related, which is less of a problem than if it were Windows-related.
I would check here: http://www.microsoft.com/whdc/hcl/default.mspx
just to ensure that the game and its drivers are compatible with Win XP. If they are - as is likely - the drivers may have become corrupted.
I would probably try uninstalling them in Safe Mode and then if, in Normal Mode, things are back as they should be, you know it is those drivers.
In that case, I would avoid reinstalling those same drivers: visit the games' manufacturer's Web site and see if you can download some fresh drivers.