Okay, here goes. A friend of mine has a PC with XP SP1 on. When he switches it on, it boots up, loads XP displays the Windows XP logon screen then suddenly reboots. This is happening contanstly No hardware or software has been installed recently, virus & spyware check are negative. I have noticed alot of posts for this type of problem but with the reboot being before the logon screen appears. I know about XP auto rebooting when BSOD is imminent so will try that tonight. Any thoughts on this problem guys would be much appreciated!