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 ...

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

Can't play MP4 on Windows? This post will show you how you can play & view MP4 video files using freeware like VLC Media Player & 5KPlayer.

Need to use third-party programs to open files on your PC? Here's how to change file associations in Windows 10 and choose which apps open which file types.

If you receive Unsupported video type or invalid file path message in Internet Explorer when using Twitch, MyIPTV, Xbox or unsupported HTML video/audio format or player, see this fix.

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.

Microsoft is making it easier to change your default file associations by adding a new search feature that lets you quickly find the extension you wish to modify.