i reinstalld my windows 7 to day (i had the 7 be 4 to) when i started up i installed all my drivers and tryd to run dxdiag to see if it was installd. here where i saw the problem it installd dx 11. and my 8800 gt only supports dx10. then i installd my call of duty modern Warfare 2 to see if it cud run with the dx 11. i got this error: DirectX
encountered an uncoverable error.
i haven't played call of duty 6 yet but I've played call of duty 5 and in the Readme of that I red that it needs directx9 and even if you have directx 10 ,you should install directx9 not 10
cod mw2 also needs directx9 and not the directx11
so if you want try installing the latest directx9 from microsoft.com or install it from the game's DVD/CD and see if it runs
but make sure to uninstall the game 1st ,then install dx9 and restart your computer,and then reinstall the game