If every time you try to play a video it says "the specified stream type is not recognized," or you have problems seeing or hearing the content, then you might need the newest Windows codec (the compression algorithm for the media file). Download the Windows Media 9 codec from Microsoft.

When you first attempted to install Windows Media Player, you may not have had the necessary permission to install software or your Internet security may have been set to "Medium" or "High." This will prevent the codecs from being properly installed. Change your Internet security to "Low" during the installation process, or see your network administrator for proper installation.