this is going to be a lengthy post as i will try and be as informative as possible. system windows xp service pack3 motherboard asus m2a-vm cpu amd 500+ ram 2gb patriot hd 160gb eide ok my problem is my computer restarts by its self. it happens when i boot up in the morning or when i shut it down. it will also happen when i load up my sim racing game. i have attempted several things 1.disconnected case usb's from motherboard. now reconnected 2.disconnected restart wire from motherboard now reconnected 3 switched ram to different slots switched back 4.installed new dvd player 5.tested resistence on power supply wires. all good 6.removed all usb devices. still restarted 7.remove modem to disable internet. still restarted 8.ran glarys utilities,avg,ccleaner,adware, no virus,etc. 9. switch power cord still restarted 10 check log file in windows no information logged 11.updated motherboard and video card ok i think that covers all i have done now to describe the problem. oh and the computer is clean and stays cool so not a heat or dirt issue. this usually happens when i am booting up my computer. i don't always get the same message. and after restarting several times it will run for long periods of time. sometimes it will just restart as if i manually restarted. sometimes it will give me a usb over charge message, sometimes it will say i may be overclocked(i have not overclocked) sometimes it will go to start windows normally or safe mode. i have tried safe mode still restarted. sometimes the computer fans will be on but monitor is black and no activity on the hard drive light on the front of the computer. i am at my wits end and any help is greatly appreciated. Within 10 min. of this post, computer restarted twice. Both times no activity on the hard drive light on front of computer, black screen, had to manually power down and start. Start windows normally screen came up, computer booted to desktop and immediately restarted and repeated process.