Drivers for audio and video are causing lockups and restarts in Windows XP

Almost everyday and sometimes more often my computer will simply restart. When it comes back on I send the error report and it says that the problem was caused by an unkown device driver. Until recently I had both the audio and the video drivers installed and running. I disabled the audio through windows(not through the BIOS) and when it happened again the error report came back as saying it was the video driver and to change some things(like update the driver and Manually decrease the hardware accelorator for your video adapter) I did the first and have no idea what the second means so i went into the BIOS and set the Video from auto to 32MB enabled. All day yesterday I had no problems until I turned my sound back on and then it locked up on me after about an hour. Then I restarted and turned off the audio in the BIOS and when i started limewire and it was checking the file contents of old downloads and it locked up on me. I was previously having the same problem with my torrent downloader and the lockups and restarts happened so often I finally gave up and reformated my harddrive. Then I had so many problems reinstalling that I don't even want to get into it. Can someone please help me cause the only thing i can think of that it could be is the motherboard. Do I have to get a different one or will getting a sound and video card do the trick.