How to Install a Windows Media Player MP4 CoDec

Microsoft Windows Media Player does not support an MP4 video CoDec. In order to make it work you need to install an MP3 CoDec manually.  

Install an MP4 CoDec using the K-Lite Mega Codec Pack

Please note that the K-Lite Mega Codec Pack is not an official release from Microsoft. However, it is a highly supported and a very frequently updated pack. In fact, a recent survey on a technology site showed just as many users using this pack as the official Microsoft pack.

  1. Go to or You can download either of them.
  2. Click the Download latest version link near the top in the right-sidebar.
  3. Save the EXE to your hard drive. Double-click it to begin installation.
  4. For non-experts, it is highly recommended to just install the recommended setup by clicking “Next”.


Rate this article:

Last updated .

Follow Will.Spencer on
  • steve2

    EXCELLENT! Thanks!

  • elitepurge

    Exactly what I was looking for. Many thanks c:

  • Wayne Fuller

    It seems to me that this instruction needs to be updated. When you go the “, Downloads & Trials, and then the Download Center”, there is NO left anything that says “Windows Media.” When you do finally get somewhere that looks like it MIGHT be what you are talking about, what you download gives you the message described in Comment #3 above.
    ??????????????????????????????????????????????????????? :sigh:

  • hammbone4266

    I just went to downloaded their codec installed and it worked perfectly on my wmp im usung windows 7 64 bit theres a link above says windows 7 codecs

  • steve hayes

    The illustration is of Media Player Classic

    I think this articles referes to uSoft Media Player versions 10, 11 etc, so the picture gives me some doubts

    Otherwise its looking good thanks

  • Qasim

    Fantastic , great , and superb
    It is working. Now I can watch mp4 videos.I am thankful for these information and download links. I hope you will add some more important links for some other important items.
    Thanks a lot

  • Nick Lewis

    Nope. I’v downloaded the Codec Installation Package for Windows Media Player 7.1 or later and installed it and followed the instructions.
    I use Windows XP and still can’t play my mp-4 video files. When setting up the media player for the first time it gives you a list of file extensions to play and nowhere in there is mp-4.

    Totaly useless.
    Why on earth microsoft can’t make things easy and just include an mp-4 extension for media player automaticly is baffling! Most phones only have mp-4 extenions, how the heck are you suppose to play them on your computer??

    • memenode

      I agree MS should probably include this by default. If it doesn’t work in Windows Media Player though I recommend you just download and use VLC for those files. VLC is widely known as a player that plays everything and it’s invaluable on any computer because of that.

  • Mendo_Nut

    MP4 files “No Workee” with XP Pro & WMP 10 with the “Codec Installation Package for Windows Media Player 7.1 or later” …. bummer.
    I give the VLC Player a try.

  • vipin

    The instructions are great. Solved the problem I had with playing mpg4 on windows media player.

  • xew

    Fun to be in China but there with out a VPN connection this link to the K-Lite Mega Codec Pack does not work…:S
    Divx is an option would it not be that you get all in Chinese because they link you to it at the divx webpage ( why nobody can tell or knows )..
    love to have it still because i need it.Anything would be fine…..

  • Wayne Fuller

    Tried once again to get this codec using the links on this site.
    When I follow the link “Download Codec Pack here” above, it take me to the site “VideoBuzz.”
    When I get there and click the “download here” button/link, I get a “Malicious Web Site Blocked” from NORTON.

    Once again ??????????????????????????????


  • khaled

    thankes alot exelant

  • ron

    the codec upgrade does not work for XP with Media Player 11

  • James Martin

    I tried to download and install the codec for .mp4 files so that I could edit them with Windows Movie Maker version 6.1 (build 7601: Service Pack 1). When I tried to install the file (after I went thru the genuine verification process) it told me that it was able to be installed only on Windows 2000, Windows XP, or Windows 2003 Server.

    Can you please tell me how I can solve my problem?


  • Liberty Emily

    Another way to play mp4 in windows media player is to convert mp4 to
    windows media player more supported format like wmv, avi

    iDealshare VideoGo is just the right MP4 to Windows Media Player
    Converter which can convert all kinds of MP4 video to Windows Media
    Player supported video format WMV, AVI, ASF, MPG. Besides converting MP4
    to WMP video format, it also can convert MP4 to Windows Media Player
    supported audio format like WMA, MP3, WAV, AU, and AIFF.

    Moreover, this ideal MP4 Windows Media Player Converter also helps
    to convert other Windows Media Player unsupported format like MOV, VOB,
    DTS, RA, VOC, M4R, and etc to WMP supported video or audio format.

  • WillSpencer


    What trouble are you experiencing?

  • WillSpencer


    Both links seem to work fine for me.