If you are having trouble playing back HD Videos or you have picture, but no sound, then it could either be that your computer doesn't have enough playback power or you could be using an unsuitable video player.
If you still have trouble, then you will need to consider reducing to a lower resolution to ensure smooth playback on slower PCs.
Best Free Player for PC
VideoLan - Will play practically every kind of video and audion files. Free Download Here
Best Free Player For Apple
Quicktime
