BSOD when opening certain games - (CS:GO/Portal2/DiRT)

I have recently been having numerous issues booting up a few games, I get to a loading screen before my computer blue screens and reboots.

This is rather irritating, especially as I can't boot up games I have recently purchased.
None the less all assistance would be much appreciated.

Thank-you for reading.

Here is information on the error:

On Sat 15/09/2012 22:15:03 GMT your computer crashed
crash dump file: C:\Windows\Minidump\091512-25537-01.dmp
This was probably caused by the following module: ntoskrnl.exe (nt+0x4B09CC)
Bugcheck code: 0x124 (0x0, 0xFFFFFA8008440548, 0x0, 0x0)
Error: WHEA_UNCORRECTABLE_ERROR
file path: C:\Windows\system32\ntoskrnl.exe

If any more information is needed please tell me I will do my best.

Please follow this : BSOD posting instrucs: https://www.sevenforums.com/crashes-d...tructions.html

on short notice :
BUGCHECK_STR: 0x124 =
Stop 0x124 - what it means and what to try
Best link for this problem, follow through with most of which you can. Also, i used to have a similar problem. Mine was fixed by vacumming dust out of the system, even though there was like none there it worked somehow. Wish the best of luck.