movies wont play in iTunes

I have 5 movies that have come from a digital copy that came with some of my BluRay movies. I uploaded them and watched these movies on a few different occassions. No problems until recently. Now 4 of the 5 movies wont play. I click on the movie and all I get is a black screen with nothing playing. I have a Harry Potter movie, Fast and Furious, GI Joe, and Star Trek that wont play, but the Dark Knight plays just fine. Itunes was updated recently and I have the most recent version.

does anyone have any suggestions on where to look for solutions or do you have any solutions?

 

What are you using to watch them? You might need a new codec if something was updated or changed. I had that problem on my Windows machine until I downloaded the DIVX codec.

http://www.divx.com/

 

X2

 

I had a problem when I updated my iTunes and it wouldnt play rented(iTunes) movies.I had to go into my settings and adjust something in my computer.it was a long time ago so I can't recall what it was.Doesnt iTunes have a help section?I think thats how I fixed mine