My son’s computer will randomly shuts itself down and restart on it’s on and I have no idea why! He had been having some problems (he thinks he had a virus) and the system keep loosing the CMOS info. So I replaced the CMOS battery, formatted his hard drive and then reinstalled Win XP home edition. He loaded his video and sound drivers and a couple of games. You can be on the internet or playing a game and the system will just shut down and restart on its own and with no warning. He now tells me that this is one of the problems that he had been having before. Any ideas would be most helpful.