brand new system locking up...help

[hawkeye_wx]

Yesterday was my first day running a new athlon xp 1600+ system. I was playing Civilization 3 for much of the day and it was running great, but around 1am the screen just locked up. I reset the computer and started Civ3 again, but after a couple minutes it locked up again. I am quite worried, because this is a serious problem and I don't know what the problem could be. This same thing happened when I overclocked my old celeron 300 to 450, but in the current situation the cpu is not overclocked at all. The video card, a geforce 3 ti 200, is overclocked slighly(175/400 to 200/430), but I doubt that is the problem. When I was running that video card in my old celeron system, I ran the 3dmark2001 demo loop for several hours with the card overclocked to 220/470, and there was no lock up problem. I'm pretty sure I installed the cpu heatsink/fan correctly. The bios has shown the cpu to be running near 37 degrees Celcius even after running Civ3 for much of the day. Frankly, I was expecting the cpu temp to be in the 45 C range, but if the sensor is correct there shouldn't be a heat problem. Lock ups is a huge problem, worst case scenario as far as I'm concerned, so I'd greatly appreciate any help.

My system is:

Athlon XP 1600+
Alpha 8045 Heatsink w/ Panaflo 39cfm fan
2 Sunon 39cfm case fans
Soyo Dragon+ mobo
512MB DDR2100 Crucial RAM
PowerMan 300W power supply
VisionTek Geforce 3 Ti 200
IBM 40GB 7200rpm hd

[Yodums]

It may be the clocking of the vid card try running it at default speeds and see how it runs smooth or not or lockups or whatever..

[hawkeye_wx]

I lowered the video card to default clock speeds. I ran the 3dmark2001 demo in loop mode. I checked on it after two hours and the computer had already crashed/locked up. The screen was black. I am SOOOO frustrated right now.

[azhari]

DDR's are notorious for not seating right. In this case when the system warms up they could lose contact momentarilly and freeze up the computer. Try fidgeting with them to make sure they are seated REAL good. Took me an hour of fidgeting (just to give you an idea) and no more freezes. Been running Folding@Home 24/7 for 10 days and happy as a clam.