Windows Media Center (on Windows Vista SP1) had been giving me a “Windows Media Center Receiver Service stopped working and was closed” error. Looking around the Internet lead me to posts about the same problem, and all of them hinted towards a possible codec conflict. No one had an actual solution though, so I was stuck figuring it out on my own.

Note: There’s a patch that solves another different problem with the same error message. You should try that first.

If you’re having the same problem, you can try hunting down bad codecs:
Disclaimer: I’m not responsible for what you do, and I very highly recommend creating a System Restore point before trying this.

1. Get and run Process Explorer, enable the lower pane view (View > Show Lower Pane), and switch to the DLL view (View > Lower Pane View > DLLs).
2. Get and run the DirectShow Filter Manager
3. Open the services manager (Control Panel > Administrative Tools > Services)
4. Open the properties for Windows Media Center Receiver Service
5. Press Start, and then quickly change to the Process Explorer window and press SPACE (in order to stop Process Explorer from refreshing) before the receiver service crashes
6. Now, find the ehrecvr.exe service and select it
7. In the list of DLL files in the lower pane, sort by company name (click the header)
8. You need to identify the non-Microsoft codecs (asking around on a forum could be helpful). For ones that you think may be causing the problem, uninstall the software that installed those codecs. If you are unsure which software is associated with a certain codec, you can crosscheck it in the DirectShow Filter Manager which has more information.
9. Refresh the list in Directshow Filter Manager and make sure the codec is actually gone after uninstalling the software - if not, click on it and click Remove selected filter

For me, it was SageTV that broke MCE. I uninstalled it and manually unregistered its codecs in Directshow Filter Manager. (Although I’m back to using SageTV.)