Have you tried the first two solutions from the
support FAQ?
Also, a dxdiag log could have useful information.
dxdiag
Windows XP: Go to your start menu and click on run. Type in "dxdiag" and hit enter
Windows Vista / 7: Press the windows key on your keyboard
or click on the start menu. Type in "dxdiag" and hit enter.
Now click on the button that says "save all information".
It will prompt you to save a file. Save it where you can find it.
Open the file and press Ctrl+A followed by Ctrl+C to copy the contents, and paste them in a reply by pressing CTRL-V.
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