As I have previously described here and here, some folks have run into problems playing protected content after installing Update Rollup 2 for Media Center 2005. Our team has identified one potential root cause for this problem and I wanted to outline it here.
If you install Windows Media Player 10 after installing Update Rollup 2, the WMP 10 setup will revert some critical files related to digital rights management (DRM), and that will result in error messages that look like the following when trying to play protected content:
Ordinarily, there is no need to install Windows Media Player 10 on Windows XP Media Center Edition 2005 because this version of Media Center already has this version of Windows Media Player. However, we have seen some applications that include a copy of WMP 10 with their package, and unfortunately WMP 10 setup is not correctly handling a couple of cases where later versions of some files are already installed on the machine.
We are working on a fix for Windows Media Player setup so that it will no longer revert DRM files like this in the future. Also, we are working on a fix to restore DRM functionality without losing licenses. I am not sure when either of these fixes will be ready, but I will post updates when I know more.
If you have already installed WMP 10 after Update Rollup 2 and do not want to wait for the fixes we are working on, you can use the workaround in this Knowledge Base article to reset the DRM system on your machine. There is one step that should be added to that article that is not there currently - before deleting the Windows Media DRM folder, you need to close any programs that might be holding files in that folder in use. Specifically, make sure to close Media Player and Media Center, and run the command net stop ehRecvr to stop the Media Center Recording service immediately prior to trying to delete that folder.
Please note also that resetting the DRM system will cause any previously acquired licenses to be lost, so you will have to reacquire them from the content providers or restore them using the license backup and restore feature in Windows Media Player (if you made backups prior to installing Update Rollup 2) to be able to play any pre-existing protected content.
There is a new hotfix available as of 4/14/2006 that is designed to fix protected content playback issues in Update Rollup 2 for Media Center 2005. Please try out this hotfix if you have DRM/protected content playback issues in Update Rollup 2.
<update date="4/15/2006"> Added a link to a new DRM hotfix that is now available in case people find and read some of my older blog posts in an attempt to fix this type of issue </update>