I have been experiencing an intermittant problem with my AMD Athlon XP 2200+ running Windows 98SE – Every now and again the PC just goes “dead” – the monitor switches off, although the lights on the PC are still on, but it doesn’t respond until I switch off or reset. I have tried putting in a bigger power supply and I have added 2 extra case fans, and I have run PC Check and it came up clean. I have also loaded Windows XP Pro, which seems to crash much more often than 98.