Ok....i have been having this problem with my pc shutting off without warning. It is usually when i am doing something graphics intensive. I just got a new ATI 9600xt 256mb graphics card. So with the new card i ordered a new coolmax power supply (400w). My old 300 watt which i thought was the problem was the one that came with my cheap case. It started the other day i was playing battlefield 2 at full resolution, it shut off. I had to unplug the power supply and hold down the power button down for a sec to get it to restart. Today i was wanting to play battlefield vietnam, i set the graphics to high, it shuts down. This time when it did, i restarted and no usb or graphics. I pulled the ram out and put it back in, i also unplugged the graphics card and plugged it back in. Ok it restarted and it was all ok. I set my bios to fail safe, but forgot to enable the usb and onboard lan. Fixed that. I have been trying to run 3dmark2001 se and it turns off at the nature test everytime at the same point. 3dmark03 went through all the game test/cpu test but in the features test it(can't remember which one) it restarted. I am at a loss here i have added new case fans, and a new cpu fan (spire) and bought the new power supply. Thinking each time that i have solved the mystery of the turning off pc. Any help would definitly be acceptable. Is this a voltage issue to something in my box, cooling, or maybe ram. PLEASE HELP. Here is my setup
Athlon xp 2200+
512 mb mushkin 2x256 mb
Abit KD7A Mobo
2 maxtor hd 100gb total
Samsung TSh-552b dvd-+r/rw
Nec dv-5700a dvd rom
Running windows xp pro sp2
Thanks in advance