There are many troubleshooting methods if your AVI file is not playing in WMP.

If you are a Windows 8 or previous version user, Windows Media Player should play the AVI file. It was reported in various forums that this was a glitch for the users who have recently upgraded to Win 10 Operating System. However, dragging and dropping your AVI file into the Windows Media Player sometimes plays the file. Whenever you try to open the AVI video on a Windows Media Player, you are prompted with “The player might not support the file type or might not support the codec that was used to compress the file” as shown below. This is the most common reason as to why you are unable to play AVI files in Windows Media Player. VLC also supports a lot of video file formats and can play videos at high speed.If you have a Windows 10 computer, AVI files will play only on “Films & TV” application and not on WMP. This is a fast, open source, free video player and supports multiple platforms such as Windows, macOS, Linux, Android and iOS.

Therefore, you need to install a third-party application such as VLC Player. If using macOS or Linux, you cannot open AVI files as easily as on Windows because these platforms do not have an integrated application that supports AVI. If you can't open it, you can right-click the file and point to the Open With menu, then click Windows Media Player or another video-enabled application if you have it installed. If you are a Windows user, just double click on the file it will open in Windows Media Player.

AVI is a proprietary Microsoft file format, so if you plan to open it on a non-Windows system, you need third-party software.

How to open avi files windows 10