I have gotten the bad pool caller error and have not been successful in reinstalling XP. Furthermore, both my harddrives have become unrecognizable to the bios. I've tried using my harddrive on another motherboard and it fried that computer too. Seems to be a virus of sorts but from reading up on the problem, now it sounds like it might be RAM or software driver...etc.. The only software driver i can think of that has been causing problems with my computer is ATI's Wonder VE TV tuner application. Never seems to run smoothly and recently I've upgraded the drivers. With the Tuner card running it always causes a crash when i'm surfing or not. This stop error though is nothing i've seen before. My first hardrive 20gig has all my windows and utility programs. My second harddrive 200gigs has my entertainment stuff...movies, music, vids, games...etc... I've tried running with one HD or both or switched and the BIOS doesn't want to recognize them. I tried putting the HD's in my brother-in-laws computer and it looks like it fried his computer too. His BIOS failed to recognize my HD's and his HD. Not only that, but his HD starting knocking. It has to be some sort of virus?? I don't want to lose any files from these HD's but how to i back up if i can't access them?? Is the BIOS damaged?? Can I repair the BIOS?? Its affected two computers.....what could cause this?? Please help.