I been having BSOD's so I reinstalled windows 7 and for a couple days it didn't show any problems then it started to come back. I tested memory twice and it had no errors.my processor and video card don't show any signs of overheating.so I'm thinking its either the hard drive or the video card going out.it showed me so many different blue screen errors that I have no clue what it is?but I did find something when I was trying to run ubuntu 11.4. when it started I chose the try it out option and then it gave me an a bunch of errors about: "something (radeon)" which is what i have, a radeon ati 4670.
so this is why i believe it is my video card that is failing.
To rule out the GPU, do you know if your PC has an on board graphics chip? If so, remove the 4670 and then see if you are still getting the same error. Another thing to keep in mind is the driver. Have you recently updated the driver? If not, perhaps updating it will solve the issue.
Uninstall all video drivers. Reinstall the ones for your video card only. Run MSI afterburner and use kombuster to burn in the gpu. If it runs fine for an hour our so you're likely not looking at a video hardware problem but rather some other issue.
If it crashes, remove your video card. Clean all drivers out and install the ones for the motherboard. It does have unboard video.
Run Kombuster again with the gpu burn in program. If all is okay then you've likely isolated the problem to the video card. If it crashes, too, you've got another problem.
Do this under Windows 7. Don't bother with Ubuntu (not a slight against linux but Radeon drivers under Ubuntu aren't 100%).
IRQL's are usually driver related. With that said try googling the stop error codes. Those will usually pinpoint the exact issue. For me mine pointed to the storage controller which thank god was simply a bad hard drive rather than something on the motherboard.