Why can't I view a movie I purchased and downloaded?

I recently purchased a movie from the iTunes store, I was about halfway through the movie (was watching it on my Dell laptop) and closed out. I went to resume the movie later, and now just pops up a black screne, when I press pay nothing happens and the bar up top saying that its loading. I've waited as long as 30mints for it to load or sync or think or whatever but the movie still will not play. Any help as to why this is happening? Thanks.