all you should have to do, as long as you had reset the bios, is insert the XP disk that they have. It is the install disc, and the repair disk in one. Reboot, and then select the "repair" option. In my experiance, they will not lose any files or information. If during the repair process it says "cannot find xxxxxx" look at the thing it cant find and try and figure out what it is... if it is a sound driver, insert the soundcard cd....ect...