I recently built a budget gaming PC (~$600). I've built many PCs and never ran into anything like this. Here are the specs:
WD 500GB 32MB Black SATA drive
XFX Nvidia GeForce GTS 250 (http://www.newegg.com/Product/Product.aspx?Item=N82E168...)
1x2GB Kingston HyperX DDR21066
I installed WinXPP and everything was fine. I did notice that when I installed the Nvidia drivers from the CD the screen went totally black, besides an underscore (_) after a reboot the drivers were installed and working.
This is when the problems started. Games were unable to be played. I just got a black screen then a reboot. When I surf the web it is ok but sometimes I get a blue screen, nv4_disp.dll. When the PC crashes and reboots it it freezes when loading windows (the bar stops). I manually reboot it and then it loads fine.
At this point I reinstalled Windows and loaded the most current drivers from NVidia's website, 185. Still had the same issue. I tried 3 different drivers so far with the same results (from CD, 182, and 185).
Wierd things did happen with the 9600 GSO. When I loaded old games, like Oblivion, it would auto detect my video settings to the lowest. I manually put it on the highest and it ran perfectly. I also ran PassMark on it and the 3D Simple test wouldn't run at all.
1 week later it starts doing the same things as it first did. Crashes. When I run PassMark I get artifacts on the 3D tests. The 3D Simple test result is 0.03. I can't play any games or any fullscreen videos, instantly goes to a black screen (I can hear audio oddly). A minute of this and then it reboots.
When I use the onboard intel VGA it works fine (just slow, which is normal).
I can't imagine both of the cards are bad since they work fine in my other PC. It sounds like a motherboard issue but the onboard works fine. Just when I use a PCI-E card it stops working.
Any suggestions or similar problems? I've read other cases of nearly the exact same issue but no one has found the fix yet. The only constant is the Nvidia cards.
I can't RMA to newegg because I threw the packaging away when it worked for the week (bad idea, I know). But I will purchase replacements if I have to, if I know what to get next.