What would you guys say was the problem if a PC just keeps shutting off at random times? Sometimes staying on for a few seconds and sometimes a few hours. I've already tried 3 entirely different power supplies that are more than enough to power the system. It is an Intel D810EMO mobo. What would you check next? Think its a mobo problem? Thanks.

Well it looks like it's not the PSU. The next simple thing would be to find a friend willing to lend you his RAM and swap it out, or, if you have 2 sticks take each out in turn and try running the system. I have had similar problems with other 810 based motherboards and it's turned out to be RAM. Some seem not to like 256Mb all in one go whereas 2x128 was OK. Good luck

yeah it sounds like my problem. when i had the freq. of the cpu turned up it was a athlon 1900+ XP and it would crash at startup (mostly). So i would have to change it back to freq. of 100/100 instead of 133/133 and it was a Athlon 1.2, it ran fine this way and i switched my memory to DDR and it works with out any problems.

I had the same problem with my sister's Via board http://spectraimpex1.site.yahoo.net/via733mhzc3c.html that has an intigrated Via/Cyrix Samuel C3 processor (its cool that the processor is actually part of the motherboard and the heatsink is only 1/8 of an inch thick and it makes almost no heat, but it can not be replaced or over clocked), intigrated vid, sound, NIC and modem. It ran just fine with one stick of 128meg SDRAM, but another stick I tried made it just shut off at random times. Changed the RAM and solved the problem. It was really agrivating before I found it was the RAM.

Lastly check your CPU temp in BIOS, your computer may be reading high values from an overheated cpu or faulty sensor. Verify the CPU temp with room temp on a cold start (off for 8 hours), if its the same then watch it for an hour and if it stays low, less than 10C difference, then you might want to try disabling the high temperature shutdown feature.