Windows 7: BSOD Screen 0x00000124 Help ASAP Please!

Hey please i need some help , Ive recently Bought a New Computer from EBAY and im having problems with it , this only happens when i play games , Example : Crysis 2 and Amnesia Heres the code i get on the Blue screen :

STOP : 0X00000124 (0X0000000000000000 , 0XFFFFFA800838B028 , 0X00000000B620A000 , 0X000000000000135)

Please help the guy who i bought it from says its something to do with the drivers not being installed right or something like that. But on the device manager it says they are installed correctly. ;\

Computer Specs :



8GB RAM
ATI RADEON HD 5670
Windows 7
AMD Phenom X II x4 940 Processor
1TB

http://www.sevenforums.com/crashes-d...tructions.html
Stop 0x124 - what it means and what to try

RAM - Test with Memtest86+
Video Card - Stress Test with Furmark
http://www.sevenforums.com/tutorials...t-prime95.html