Hi
Your not the only one having this problem, the only answer I found was this one.
Try and see if this has any effect on the problem.
""If you're having video problems after the latest WMP update and have an nVidia card, go to WMP's Tools, More options, Devices, Performances and uncheck "Use High Quality Mode"".
I tried it and the same thing happens to me, and I can't find any Tools Menu.
If I find anything else I'll come back.
Mike