Ok, need some more information.
A DXDIAG output.
Also, any extraneous software running on the computer that is different from the default Windows installation.
Also, could you try installing 
this utility.  Install it anywhere.  It is a stand-alone utility.  Run it and press <F2> and switch to "full screen" mode, then press <F2> to return back to the window.  Let me know if that works ok.