Managed to screw up my iTunes

Some how I have managed to screw up my itunes. I can play the music and see the album cover but my itunes videos will now not play. When I click on view show current video nothing happens. It was working fine not sure what I managed to do.
Any help would be very appreciated.

Can you go back in time? (Time Machine)
Ask yourself, "Have I made any changes recently, downloaded any new programs?"

I've never experienced the problem you are having in iTunes, but I've done things in the past that caused videos to not play. Like when I bought a new camera and absentmindedly chose to only play videos on this computer with "this" program (meaning the new camera software).

NOTE: Thread moved to appropriate forum. Not just anything goes in Anything Goes