I recently built new Desktop PC. It was supposed to be for me to do simple tasks for my computer. Here are my specs.
PSU is 450WATTS and its an ATX that came with the case
Intel Celeron D 2.66 GHz Processor
MSI PM8M3-V Motherboard
w/ 3 PCI slots
1 AGP Slot
Maxtor 320Gb SATI Harddrive
and 2 RAM's
256mb
& 512mb.
Well I set up everything and everything is fine there. I had everything installed correctly and My Computer Does power up and seems to run fine. Then within 5-60 seconds the computer turns off voluntarily. All the RAM has been tested. Switched slots.blah blah. Nothing works. All forums in witch i've looked at give no solutions. The only thing i havent tried is switching the power supply. If anyone knows anything to help that would be greatly appreciated.ahhhhhh.

Now I recently experienced something similar. That Celeron D is a 775 processor right? I got a Pentium D that's also a 775. It could be that the thermal paste/grease isn't applied properly and the CPU is overheating. That was the case with me. Try removing the heatsink and removing the current grease. Then go to ...google and do a search for "How to apply thermal grease" and select the first one at the top of list. (i woudl have given you direct link but I'm not sure if that's allowed here). reapplying the grease and properly installing the heatsink worked for me. Hopefully it'll work for you.

I am having the same problem.....

did the thermal grease thing work???

by the way I purchased silverized thermal grease and the problem went away