i just built a new rig for a friend, xp installed great and all the other programs installed fine but now it restarts its self on its own. i thought it was a windows problem but i ruled that out after i switched hard drives and ram and reinstalled windows again. the screen goes black and it restarts. the temp is fine, i was watching it as it ran (mbm). it has a 450 watt ps, nf7s2 mobo, semperon 2500, and 512 ram. can anyon please help its driving me crazy.