Video playback

I love all my apple products, but am still using Windows. This is the first time iTunes has had issues with playback. Its plays a tiny clip of sound and audio. You can scrub it to different points during the film, but each time only playing a tiny fragment. If I play with my resolution or video card settings it then will tell me that I'm not H D C P compliant. I am. All other devices have no issue. What is that I must do to remedy this?