M4V VIDEO FORMAT should play on most all players and give you a higher video quality. This will let us upload a larger, crisper video that will serve both Mac and PC users, but may take longer to download. If you are having problems playing the file we suggest downloading the VLC player, which is a easy to use cross-platform multimedia player. You can get the free VLC player here http://www.videolan.org/vlc/. For more information just Google M4v video format to get the latest information.