I have an aging Dell Dimension 4700 (Windows XP SP3) that reports a Dell 0M3918 motherboard with a Prescot Pentium 4 (2.8GHz) CPU. After several power outages, the machine is not stable. It will run for 2 - 12 hours at a stretch after which, it will reboot (not clear whether CPU usage correlates to reboots). The reboots occur without warning (no blue screen or similar) and are not logged in System Events.
I've looked elsewhere for ideas on isolating this problem to the power supply, CPU, GPU or any other single component, but am without an answer. OCCT won't test my power supply (since my GPU is an integrated Intel). Any ideas on isolating this problem to a particular component or has anyone had similar failures?