I had a problem very similar...mine was showing the upper
left corner of what ever video was being played...to fix
this, I had to Right Click on the Desktop, select
properties, then select settings(doing this from memory so
might be a tad off), then there should be a
troubleshooting tab, and a slider bar with your hardware
acceleration for video and it's probably pushed all the
way over to the right, start sliding it to the left until
it works(you have to apply it each time, and then check
out the video)...I had to turn mine almost completely off,
but it fixed the video problem..
