Check out our guide on how to convert MP4 files to AVI, whether you use Windows or Mac OS X.

I was recently sent some video clips in .mp4 file format and could not open them with Windows Media Player, which displayed a message saying the file was incomplete or corrupt. I tried various ...

When you export a Windows Live Movie to disk its default settings go out to an MP4 file. Windows Media Player on his computer does not play MP4 files.

How to Play MP4 Files in Media Player. An MP4 file is an MPEG-4 video encoding used for viewing movies. It is a file compression format that provides a wrapper for video, audio and text.

Q: My sister sent to me four MP4 video files that she had converted from old family films. I was able to view them and enjoy them on my computer without issue, but when I tried to forward them to ...