To view the videos, double-click on the MP4 file, and your computer's default media player will most likely play it.

Windows Media player can play them, as well as QuickTime, and and iTunes. They can be played on Windows PC's, and Apple Macs.

HOWEVER, if you have any trouble playing them, then you should download The VLC Media Player.

You can get it here for free:  

http://www.videolan.org/vlc/

Thanks!