Can't play iTunes movies

I'm running Windows 8 64-bit with 64 bit iTunes, and cannot get my movies purchased in iTunes to play. I've uninstalled and reinstalled all programs/utilities necessary for iTunes (Bonjour, Apple device, Quicktime, etc.), but my movies, though downloaded, won't play. I can see the frames in the preview when clicking on different sections of the movie, but I get no sound, or audio, and the track doesn't advance at all.

Additionally, when I go into the iTunes store, or attempt to play my movie, iTunes asks me every time to authorize my computer, I put in my info, it accepts it, but never remembers it. It always states that I have 2 of 5 authorized, and I feel the 2 issues may be related. Any help would be much appreciated.