My config consist of ASUS A7N8X DELUXE mobo, ATHLON XP 2400+ CPU, 512MB DDR RAM. Of late, my PC is shutting down and restarting on its own. The CPU External Frequency (MHz) is set at 133MHz and the CPU Frequency Multiple Setting is set at Auto in the Bios. Is the CPU External Frequency to be set at 100MHz to prevent overheating of the CPU, which is suspected to be the cause of the problem ? Or will a new layer of thermal paste will do the trick ?