I got my computer and everything was onboard I was able to play most games but it would take a long time to load the games, about 30 mins, eventually I’d be able to play and experience very little lag or issues. I mostly played half life 2(HL2) and counter strike source. I decided to upgrade a little. I bought a 512 MB ram chip, I had only 256 before. I bought a PNY Technologies Verto GeForce 6200 256MB AGP Graphics Card. The computer booted up just fine, it played trivial games just fine, but when I tried to play HL2 it rebooted the system. I took out the ram chip, tried it and it rebooted again. I bought a new power supply 500W Antec, tried again and it still rebooted. But it only reboots when I try to play a really hardware taxing game. I thought it was because I forgot to disable the onboard video, however when I tried to find a dip switch or a bios option, there was none. I looked online again and it said that my motherboard is supposed to automatically disable the onboard when I use an AGP card. I removed the new video card, booted up like normal, disabled the video adapter in the device manager, then shutdown put my new card back in and restarted. Still the same issue. I'm more than sure I have a sufficient power supply. The ram chip is good; I tested it on another system. The video card doesn't reboot on another system, but for some reason it reboots on this particular system. Does anyone have any helpful advice for me? Shallow Mind + Deep Thoughts = NULL;

6200 256MB AGP is not a good card to begin with, so I suggest you buy at least 6600gt AGP or 7600gs AGP for better performance if you can return that 6200 AGP. The next thing I would try is to disable AGP Fast Write and see if that solves the problem. Maybe turn from 8X to 4X AGP? Have you update to the latest driver 93.71 from www.nvidia.com? What about your motherboard chipset driver, are those latest as well? TMP-Man Asus P5P800-SE PAT P4 506 @ 4009Mhz 1.3625v Thermaltake CLP0024 w/ 1700RPM 92MM + AS5 2GB OCZ 2-3-2-5 DDR400 120GB/300GB 7200RPM HD Leadtek 7600 AGP 590/1600 VF700 ALCU AS5

"6200 256MB AGP is not a good card to begin with, so I suggest you buy at least 6600gt AGP or 7600gs AGP for better performance if you can return that 6200 AGP." but thats not the reason it causes the PC to reboot. i was using geforce 5500 when i 1st got HL2. although the game was kinda lag(not that bad, it was OK actually), but it didnt reboot the pC.if this is the only game that causes the PC to reboot, i would suggest you to upgrade the video card to the latest version. then reinstall directX. if this doesnt fixed, check the soundcard. because i had a similar problem with my old game called Evil Genuis. everytime i started the game, the whole PC reboot. then i found out because of my soundblaster, when i disabled soundblaster and use onboard soundcard, the game ran fine. after upgrade my coundblaster, the problem solved as well. so check your soundcard.