When sitting idol for an evening, this 5 year old Gateway PC simply clicks off, just like we had a power outage. It's happened 3 times. Power outage isn't the problem however as a professional UPS is in use. On the reboot, the DOS commands pop up offering alternatives for rebooting since the shutdown was forced. My question is: Can this be an early sign of the mother board going out and if so, is there a test to perform? Other than the problem as stated, nothing else out of the ordinary has happened. Suggestions? I have attached a full description of my PC.