The Player has tried to automatically download the codec from the codec server, but the codec is not available for download. Typically, this error message is displayed if the required codec is a non-Microsoft codec. Non-Microsoft codecs are constantly being created and improved for a variety of digital media formats, so it is common to not have the necessary codec to play a certain file.
To find codecs, click the Web Help button in the message. A Web page on WMPlugins.com opens and displays additional information about the missing codec. If the manufacturer has registered the codec with Microsoft, you will be able to download the codec from the Web page.
Note Sometimes when the Player can't play a file, an error message is not displayed. Instead, the item in Media Library turns orange and an exclamation point (!) is displayed. To display the error message, right-click the file, and then click Error Details.
If the manufacturer has not registered the codec with Microsoft, the codec identifier (either a FourCC code or WaveFormat ID) is displayed on the Web page. To find non-registered codecs, do the following:
Go to the Registered FourCC Codes and WAVE Formats Web page on the MSDN Web site.
Find the codec identifier (FourCC code or WaveFormat ID) on the Web page.
Review the additional information provided for the codec identifier, such as the manufacturer (Company Name) and Description.
Use this information to search the Internet for a trustworthy software provider of your codec.