I built a system about 5 years ago for my wife's cousin. She recently indicated that the computer kept shutting off. At first I thought that she had picked up a big but that was not the case. I did change the pwr supply,hardrive,disconnected all the peripherals and to no avail.I also added extra artic silver to the CPU.I guess I need to look at the mobo/processor, but there wasn't any indication of overheating. I monitored the CPU fan and it was operating above 2200 rpms. Any help would be appreciated.