Every time I try to start my comp it starts loading up fine then my whole comp restarts i didnt know if this was a problem with the hard drive or not...! It has been working fine until yesterday...! I was cleaning my heatsink and accidently knocked it off I replaced it immediately but never replace the thermal compund. When I started up my comp made a wierd warning noise so I turned it off. I put new thermal compound on and now when I start up when it gets to the login screen it just restarts...!