Media Center crashes when launched after installing KB908250 and KB910393 from Windows Update

I mentioned yesterday that there is a new Windows Media Player hotfix (KB910393) available that will help reduce instances of digital rights management problems in Update Rollup 2 for Media Center 2005.

We have found a problem with the way the setup package for this hotfix interacts with Update Rollup KB908250 for Update Rollup 2 that can cause Media Center to crash when you try to launch it after installing KB908250 and KB910393 from Windows Update.

Problem description

In this scenario (described in this newsgroup posting), after installing Update Rollup 2 for Media Center 2005 you can visit Windows Update to search for additional updates. There will be some new critical updates available that are only offered after you install Update Rollup 2. Included in this list of critical updates are both KB908250 and KB910393. If you accept the default settings, Windows Update will silently install each of these hotfixes and then reboot at the end. However, after the reboot, you will get an unhandled exception and Media Center will crash if you try to launch it.

How to workaround the problem

In order to repair your system and fix this crash, you can one of the following sets of steps:

  1. Download KB908250 and re-run it
  2. Reboot

-or-

  1. Click on the Start menu, choose Run and type cmd
  2. Run the command %windir%\system32\spupdsvc.exe /install "Enables Service Pack Installer to complete its scheduled post-reboot tasks"
  3. Reboot the system

Root cause

The reason Media Center crashes in this scenario is that the computer is left in a state where critical Media Center services (ehRecvr and ehSched) are not registered on the system. The setup package for KB908250 runs commands to unregister these services, and then schedules a process to re-register them after the system is rebooted. However, there is a command in the setup package for KB910393 that un-schedules the process that KB908250 schedules. Therefore, the command to re-register Media Center services after the reboot never happens.

You can verify that you are running into this exact problem by checking the following:

  • Run sc query ehrecvr and verify that it reports that ehrecvr is not an installed service on your system
  • Run sc query ehsched and verify that it reports that ehsched is not an installed service on your system
  • Look for a file named %windir%\system32\spupdsvc.inf and verify that it contains a [ProcessesToRunAfterReboot] section with commands to run C:\WINDOWS\ehome\medctrro.exe /p /f C:\WINDOWS\INF\KB908250rg.inf RunOnce, C:\WINDOWS\ehome\EhMCXIns.exe /i and C:\WINDOWS\system32\spupdsvc.exe /delete

This problem will only occur if you install KB908250, suppress the reboot at the end, and then install KB910393 afterwards. Unfortunately, this is exactly the way that Windows Update currently installs these 2 hotfixes after Update Rollup 2 is installed.

We are still working with the Windows Update and Windows Media Player team to identify the best way to fix this issue. I will post an update when we decide the right course of action. I apologize for the inconvenience that this issue is causing.