Ok so I have a computer that is powering down by itself. It was an Emachine T6532 that well, went thru a house fire. I rebuilt it into a new case, but it has the original CPU, MoBo, HDD, and up until recently the original power supply. I have added an Ethernet card, and a sound card. Its running Window XP Pro sp2 I have had it running just fine for about a year now. Ok so as i said it started shutting off on its own. This just started happening last week. So last Friday i replaced the power supply with a 350 watt Antec one. Booted up ran fine all week. So I thought my problem was fixed. Came home today, my girl friend hopped on that computer, was on it for about 5 sec and it powered off by itself. Personally I think its a over heating issue, since it wont power back on for 5-30 minutes after it shuts itself off & I also leave it running 24/7. If it was a virus issue I would think you could power it right back on. And since I just replaced the power supply, I'm going to guess that's not an issue. Also, I don't think its a Mobo issue, since again I would think I could power it back on after it dies to, and at least get fans turning on. As it is when I hit the power button on the front, it acts like there is NO power to the machine at all. So then if it is a over heating issue, what do I do to narrow it down to see what needs to be replace. Or does its sound like its not an over heating issue? Any help would be great, and if you need more info let me know. Thanks!