Hey guys! I built my 2nd computer yesterday. I put my HDD in it and wait for a boot up. It gets to windows xp and then it restarts. This happens over and over and over again. Thinking that it might be a corrupt file or something, I put a different HDD in it and it boots up windows vista ultimate. (I have like 7-8 hdds) Looks like a bad driver or a corrupt file. I try the hdd with different hardware and it boots up. Hmmm, sounds like XP compatibility to me.