More details of the 0xA STOP Error here, (if that is what the STOP error code is);
No expert myself, but it could be a driver error, and more guidance from Microsoft is below. It may help point you in the right direction;
If the problem is confined to video intensive problems, has the video driver become corrupt? What does the Device Manager say?
Okay, well this weekend my computer contracted a virus (Fraud XP.Antivirus) relating to downloading a faulty copy of Avast! Antivirus. Since then I have fought the virus with Spybot S&D, AVG, and Malewarebytes. I have removed the virus and am now dealing with a more serious problem, I am getting the crash IRQL_NOT_LESS_OR_EQUAL when trying to run system intensive programs like video games. Also, my Windows Disk Check and Windows Defragmenter are not working. So far I have tried multiple anti-virus, anti-spyware, etc. I have also tried booting in safe mode, booting with all services running, and other basic diagnostics. I am running out of ideas however.
I am running-
Dimension 8600 Pentium IV 3.4 GHZ
2 Gig RAM
Radeon X1300 256Mb
Integrated Soundmax Sound
Phoenix ROM Bios