I've already read like 15 different threads around Google about this problem but none of them really sounded like my problem. What happens is that sometimes when I'm just using my computer, whether it be gaming or browsing the internet, it will restart randomly. Sometimes it will shut down and not even start up again. I don't think it is an overheating problem because it happens no matter the temp. of my cpu. There are no errors, no blue screens, just sudden shut down. It wasn't too much of a problem before, but just now when I was playing TF2, it "stopped working" and then my computer restarted. As it was starting up again, it restarted again. While it was booting up for the second time, it shut down and didn't wake up. I pressed the power button and tried to boot it up again, but it said something about corrupted startup files and ran startup repair. Now it works, but I want to know what could be the problem. Running Windows 7 x64 build 7100 (RC). EDIT: Just restarted about 4 times in a row, I was playing Prototype for the first time and it restarted barely 30 seconds in. I logged in and tried to test with Prime95 and it restarted almost immediately, before I could double-click on the .exe. Logged in again and tested without a restart, finally, within 2 minutes 2 of the 4 threads failed. Might have something to do with it. Tried to post here, restarted again. EDIT2: Restarted a bunch of times again and had to launch startup repair, again. Could this be a power supply problem? Everest reports the +12v voltage at about 9-10 volts. What happened: 1. converting some music, restarted in the middle. 2. after just logging in, opened the app i was using and it restarted. 3. during startup, it restarted 4. did not even boot up this time, the computer just got stuck during POST. Reset button or holding power button down did not work - had to unplug computer. 5. after trying to boot up, it told me to launch startup repair. Restarted immediately after pressing enter. 6. launched startup repair again, restarted while launching it. 7. currently running startup repair, hoping it wont restart again... EDIT3: ok, now this is starting to get ridiculous. startup repair was successful, but then after I logged in it restarted after about 5 minutes. Shut down the computer now, and I'm pretty sure I can smell burning coming from inside the case. can't tell what it's coming from, though. help, somebody!