Ok, I thought I knew everything (almost) until I ran into this bugger.
Here is what I have:
IWill XP333 board
64MB Nvidia Graphics card
2 256mb dimms from OCZ PC 2700 DDR
Windows XP Pro (NTFS)
Built this system for a friend. Everything ran fine from February to June. In June PC started acting up. Random reboots, graphics went to 640 X 480 at 4 bit, wouldn't always turn on, CMOS put CPU at defaults (1150MHZ at 100 Mhz).
He decides to tell me after a month of this happening.
So, I change CMOS to 133Mhz and CPU jumps back up to normal. I fix the video card problem by uninstalling driver and letting Windows reinstall. Got video at 32bit 1024 X 768.
At this point I am rocking and rolling. Then it reboots and reboots and reboots whenever it likes.
I take out a DIMM leaving one 256 module in. Using Sisoft Sandra 2002 I stress tested it for over 24 hours with no problems. Swapped the memory modules around stress tested for 24 hours and still no problem.
As soon as I add the second DIMM, I can get it to crash and reboot by running a cache/memory benchmark, or by just using the computer normally for awhile.
I have tried every DIMM slot combo. I have replace the power supply with a 430 watt.
I am thinking this is a hardware issue, but I am looking for any ideas. I will try 2 different DIMMS this evening.
This defies logic, but sometimes computers do. Maybe I am not thinking this through. Everything is fine with one DIMM in and in any DIMM slot. Put 2 in and random reboots consistently.
Any suggestions would be appreciated.