Each media fie you play using Windows Media Player is compressed and decompressed by a special file known as a Codec. Codecs allow media files to be transmitted via the Internet and other means as a file that takes up less space. Once the media file is on your system, it is expanded by the Codec present in Windows Media Player. Codecs are automatically downloaded into your computer's media player, but you can manually download Codecs if you are experiencing problems playing files in Windows Media Player.
Close any open programs and files.
Click "Start," "All Programs," "Internet Explorer."
Note that Internet Explorer is the only Internet browser that can complete the Microsoft Validation required before downloading the Codecs pack. Firefox or another browser cannot access and download Microsoft.com files including updates.
Click on the "Codec Installation Package" link in the Resources section of this article.
Click on the "Continue" button to start the Microsoft Validation process.
Click "Install" when the "Internet Explorer---Security Warning" dialogue box appears.
Click the "Download" button when the "Codec Installation Package" page opens.
Click "Run" when the "File Download---Security Warning" dialogue box appears. The Codecs pack will download.
Click "Yes" when the "Windows Media Player Codecs Setup" dialogue box appears.
Click "Yes" to agree to the license agreement. The Codecs pack will install and prompt you when the installation is complete.
If you are prompted with an error or informed that the Codecs update is not compatible with your computer's version of Windows Media Player, click "Cancel." The Codecs package will still install and transfer the Codecs it can for your computer's version of Windows Media Player. You will receive a prompt when the installation is complete.
If using Windows Media Player 11, the Codecs update package is not compatible. Windows Media Player 11 automatically updates its Codecs as needed. If using an older version of Windows Media Player (below version 7), click on the "Windows Media Download Center" link in the Resources section to select the Codec package for your older version of Windows Media Player.