Frank_Rizzo - 7:45 pm on Jun 22, 2010 (gmt 0)
I don't think it would be the bios. Bioses don't usually go faulty. They can get corrupted but not usually faulty.
In no particular order of preference I would say these are faulty:
RAM - try less sticks / spare sticks
Mother board - capacitors may have dried out by now.
Can you boot to a diagnostic floppy, CD, or another hard disk? You need to run something like memtest.org