The easiest way to play MP4 files is to double-click the MP4 and let your computer decide which default application should open it. Since most people already have Windows Media Player or QuickTime installed, the MP4 should open automatically.

However, if no program opens the MP4 file then you probably don't have a program installed that can view and/or edit MP4 files. We recommend installing one of the programs mentioned above, or the free VLC player, which is a fantastic MP4 file player that supports not only this video format but many others, including audio files. MPlayer is another free MP4 playe