I've seen that many people have had this problem before but still cannot find a solution.
After installing a screen capture software my DirectDraw was disabled.
I've already installed latest videocard drivers (Geforce9800 GTX), apparently there is no way in Vista 64 to Enable/disble Directdraw/Direct3d.
The 64 bit Dxdiag shows no problems but there is no way to re-enable DX at 32 bit.
Any help is really appreciated