WINDOWS MEDIA CODECS - Microsoft Windows Media Player

Developed and designed by Microsoft, Windows Media player (WMP) is an amazing application that is used for playing video or sound as well as viewing images in your computer running Microsoft Windows Operating System, Pocket PC and Windows mobile-based devices. This application also has had editions for Mac OS X, Solaris and Classic Mac OS, but they are discontinued. Windows Media player supports different kinds of file formats in audio and video media, including WMV, WMX, WAX, Windows Media Metafiles, AIFF, Windows media audio and video files, AVI, MPEG, MIDI, MP3, DVD video, CD audio track and UNIX.

You can check the supported formats above and download codec accordingly.

BTW, here is the guide teaching you How to Convert YouTube video to Windows Media Player?

Windows Media Player is a popular player developed by Microsoft company, but actually it cannot play all file types. For example, it fails to support h.264, h.265 (popular video codecs on YouTube), dvd media, iso, vob, vcd (windows media player doesn't play DVD), mkv (attached support on Windows 10), rmvb, rm, swf, webm, etc. So you may run into troubles when playing such non-supported files with Windows Media Player. That's why you need a codec pack for Windows Media Player.
Where to Download Windows Media Player Codec Pack?
1. CCCP
2. Media Player Codec Pack.
3. XP Codec Pack.
4. K-Lite Codec Pack.

Windows media players seem to have a prob. with having all the codec you might need to play a movie. ...even after you install more codec. ....go to the site for VLC media player and download it and you it as a default player. ....vlc media player has all the codec's in it that you would ever come accross. ....works great for me and has never found a movie it could not play