From Convert Audio Free:
With Windows 8 codecs pack, choose a few simple settings and have windows media player playing all your favorite movies, and clips. Windows 8 codecs also checks your system for other codec packs installed and offers the user options if other codec pack is installed. Windows 8 codecs pack will do its best to get your video files playing correctly regardless of your current computer configuration; however it can not solve every codec and registry problem that a user may encounter on their system. We recommend that users with registry problems attempt to clear up their registry then try installing windows 8 codecs in order to create proper associations. Windows 8 codecs also includes the option of adding MPC (media player classic) to your system for a more rewarding playback experience than just windows media player alone. All options are configurable inside the installation kit.