Hey Guys,
 
I'm having some trouble with my new system and I was hoping I could use your extensive knowledge for help.
 
I have a MSI k9a Platinum motherboard with updated bios version 1.8.  
 
I just upgraded my system and It hangs every once in a while while playing any 3d games. The game still runs as far as I know, but the display goes black. The harddrive access light still blinks and sometimes the sound continues to play. I tried looking in the Alerts in windows to see if there where any that could help me diagnose the problem, but since the computer is still running I need to restart it using the reset or power button I never get an alert. I never had the problem until I upgraded my system.
 
I used to have:
x1650 pro ATI 512 ddr2 video
3800+ am2 x2 processor
500 watt generic power supply
Twin 1 gb 6400 corsair ram sticks for 2gb of ram
1 80gb WD hardrive
1 500gb WD harddrive
 
I upgraded to a:
EAH3870 top/g/htdi/512m/a Asus video card
AMD6400+ am2 x2 Processor
 
I have called Asus and MSI tech support and have gotten no where. Asus says that they don't know the motherboard I'm using and it might not be compatable and MSI has told me that there are no known issues with that combo.
 
I ran memtest to make sure it wasn't ram.
I can run 3dmark06 and It doesn't crash.
I have checked the temperatures and nothing goes above 55c
I downloaded Riva tuner to crank up the fan to make sure its not overheating.
I used to run windows xp home edition. When I did the upgrade and thought it might be some old drivers in the system causing the crash. I reformatted and now have windows xp64 professional.
I tried the newest ATI drivers from the AMD/ATI website with problems.
I also tried the latest Asus certified drivers for the video card. (Which are about 2 updates behind ATI)
In windows(dxdiag) and catalyst control center it recognizes the video card as 1024mb of ram. It only has 512 of ddr4. The only programs that recognizes the video cards correct amount of vram is Rivatuner and 3dmark06.
I can do any sort of windows program that doesn't involve 3d graphics. I can transfer files, defrag, virus scan, watch movies/anime, word process, and burn dvds/cds without any issues.
 
I'm sorry if I forgot any details that might be helpful, but please just ask and I'll throw it up here.  
 
Thanks for any help,
Kewlfrog
 
 

Your PSU rises a red flag. It may be ok with the old gpu, but probably the new one. If you can, try your gpu in your neighbor's/friend's/family's pc or get a good one:
 
http://www.xtremesystems.org/forum [...] p?t=108088
 
What ASUS implies is that they probably didn't bother to test their gpus in their competitor's mobos.
 
Look for any sys/app alerts in Event Viewer in Control Panel > Admin that happened around the time the system froze up.
 
Update Windows & your games. Don't worry about dxdiag. As long as its test check out, the gpu is ok.
 
Oh, did you get the 2 AMD drivers for the dualie?