When I try to start my PC an hour or more after shutting down, it is not booting. Power is on and all fans inside the cabinet are working, and the voltages seems to be normal in the SMPS. If I wait for more than four to five hours it will start working, or only the next morning. I tried resetting the CMOS, but to no avail. Tried also opening the side cover and force cooling, but no joy. My config is: Core 2 duo E7500, Intel DG41RQ , GeForce 9600GT graphics, 2X2 GB Kingston, Gigabyte GE-R460-V1 power supply, LG DVD, Syncmaster 2033 monitor. Mine is XP SP2, Avast anti virus, and Spybot search and destroy.