Im building a new computer for my friend, and i got all the parts in, but when i turn it on, it will run for a while and then shut off on its own. When i try to install windows it will get through part of the "loading install files" section, and then shut down. When I checked the temps of the cpu in the bios it has it idle at 89 degrees celsius. I cant figure out what the problem is.
At the same time I built my other friend the same computer with a different power supply and his works just fine.
Motherboard: Gigabyte p55a Ud4p
CPU: Intel i5 750
PSU: Corsair TX 650W
Graphics Card: Sapphire radeon 5770
Ram: RipJaws 1600mhz, but running at 1333mhz
HDD: Caviar black 1tb
Disc drive: Lite-on dvd burner
agreed with above. Your mobo is causing the computer to turn off before burning the CPU up. The stock heatsink should have come with some strips of thermal grease. Hopefully you didnt scrape that off or anything.
If you used a different heatsink, as noted above... you definately need some thermal paste in there.