The MKV or Matroska Video container format is not natively supported by Windows Media Center. However, with the assistance of a software component known as a media splitter, files with the MKV container format can be played. The media splitter works by separating the video and audio feeds. The only limitation when using a media splitter is that it only works when using the Windows Media Center to view the MKV movies on your computer. It will not work when using extenders of Windows Media Center such as the Xbox 360.
Download and install the codec pack provided in the link in the resource section. The codec pack contains the necessary MKV codecs and media splitter required for you to play MKV files.
Download the correct registry file for your version of Windows 7 from the link provided in the resource section. If your computer is running the 32 bit version of Windows 7, download the x86 registry file. If your computer is running the 64 bit version of Windows 7, download the x64 registry file. The registry file will allow you to view MKV files in your media center library.
Double-click the downloaded registry file to install it to your system. Once the codec pack and registry files are installed, you can now view MKV files in your library and view them on your computer.