I am using windwos xp pro with sp2 and norton internet security protection tool. but my pc shuts down within 10 seconds of starting without any valid reason and then it restarts itself. It does not shut down completely, but this cycle of starting and then restarting continues to no end. I did restart and turned it off many a time, but it still continues to shut itself as soon as it starts. Can any one help? There are no viruses or any thing else. The cpu temp in bios is also set to the maximum and I am not playing any games or doing temp intensive work at all. I have not changed any setting in bios recently. All I am doing is just normal surfing etc. Thanks.