Its a simple solution Having now got my Call of Duty 4:Modernwarfare to work on my Win 7 64-bit by simply installing Dirext 9.0c (yes its true, Directx 9.0c installs completely seperately without interfering with Directx 11). I now find all my other Directx 9 games are playing absolutely...
Had the same problem guys and I have now installed Directx 9.0c too. Glad to say games now work well too. Would have been nice if Microsoft website can make this clear-cut to everyone that if a game needs 9.0c, its fine to install regardless if you higher versions. Gosh thats my first post...