Missing MPEG-4 Codec in Windows Media Player 10

The Windows XP Embedded Service Pack 2 Feature Pack 2007 release includes Windows Media Player 10 (or simply referred to as WMP10). WMP10 does not include an older Microsoft MPEG-4 codec (because this file took no changes between Windows Media Player 9 and WMP10) and therefore certain media files (using the .ASF file extension) cannot be played back. 

On your runtime image built with WMP10 released in FP2007, when you try to open and play back certain media files for the first time (e.g. .ASF files) encoded with the older Microsoft MPEG-4 codec, WMP10 will automatically download the Microsoft MPEG-4 codec and display the following dialog box:

If you click the “Install” button then WMP10 will install the downloaded codec into your system environment and you can play back the media files properly.

If you click the “Don’t Install” button then WMP10 will not take any further action and therefore you will still not be able to play back the media files.

The Dialog Box May Not Appear

Windows XP Embedded Service Pack 2 Feature Pack 2007 also includes another new component called “Message Box Default Reply”. If you bring this new component into your target configuration, depending on what setting has been configured for this component, all message or dialog boxes may be suppressed and prevented from displaying to the users. For the dialog box above, since its default action is “Don’t Install”, therefore WMP10 will not take action to install the Microsoft MPEG-4 codec. Please bear this in mind if you have the “Message Box Default Reply” component in your target configuration and you need to use this MPEG-4 codec for playing your content.

- Thomas