This is the PC Hardware Forum so I think you are suspecting a hardware issue. If you can, run the memory test from http://www.memtest86.com
Also, try a KNOPPIX boot CD (noted widely on google.com) so you can tell if an OS issue is in play. Some catch a worm/virus and don't know it.
Bob
During the hurricane Frances, my PC kept losing power after every power surge despite APC battery which should give me 18 minutes of back up time on teh battery. Suddenly my system kept booting by the time to load the OS it will restart the boot process and finally display the following blue error screen: DRIVER_IRQL_NOT LESS OR EQUAL .... PHYSICAL MEMORY DUMPING. I can boot in safe mode I have removed some software and drivers did not resolve the problem as well as changing the memory card. Need your help to resolve the puzzle.

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