One specific cause of ehExtHost crashes that can occur when launching Media Center

A while back, I wrote a blog post describing a scenario where launching Windows Media Center causes a crash dialog to appear with the title ehExtHost.  At the time I wrote that post, I had not found any specific add-ins that consistently caused problems.  However, since then, I have heard from many customers seeing this type of crash, and all of the crashes so far have been caused by a specific add-in.

In the scenarios I have seen, the customers had computers that came pre-installed with a Symantec Norton anti-virus software package.  They had uninstalled this software package, and the crashes started happening afterwards.  This anti-virus software includes a Media Center add-in so you can access the settings from within Media Center, and the uninstall process appears to remove the files but leave behind the Media Center add-in registration information in the registry.  Because the registration is still on the system, Media Center will attempt to launch this Symantec add-in each time it is opened, but since the files have been removed, the add-in will crash.

If you have a Media Center system, and are seeing ehExtHost crashes when you open Media Center, and if you have previously uninstalled a Norton anti-virus package that came pre-installed on your system, you can use steps like the following to resolve this crash:

  1. Click on the Start menu, choose Run, type cmd and click OK

  2. Run this command:  reg delete "HKLM\Software\Microsoft\Windows\CurrentVersion\Media Center\Extensibility\Applications\{4874559d-e801-4f21-a580-6f5f0b87017c}" /f

  3. Run this command:  reg delete "HKLM\Software\Microsoft\Windows\CurrentVersion\Media Center\Extensibility\Categories\Background\{51537886-fe58-4b67-9fbc-567013c765f6}" /f

  4. Run this command:  reg delete "HKLM\Software\Microsoft\Windows\CurrentVersion\Media Center\Extensibility\Entry Points\{51537886-fe58-4b67-9fbc-567013c765f6}" /f

The above steps remove the registration information for this particular add-in from the 3 locations that it has appeared in the registry on all of the systems that were encoutering ehExtHost crashes that I have diagnosed so far.

If these steps do not help on your system, please refer to my previous blog post for a list of steps you can use to gather additional information that can be used to narrow down the root cause of this type of crash.

Comments (9)

  1. DFu says:

    You should also be able to use the Media Center UI to do this.  In MCE2005, go to Settings, General, More Program Options, Edit More Programs.  You’ll see a list of installed programs and add-ins there.  Just disable the Norton A/V application.

    In Windows Vista, Media Center will ask you if you want to continue to use the application that has crashed.  If you don’t want to continue using it, Media Center will automatically disable it for you.

  2. LTBV01 says:

    MediaCenter UI in MCE2005 allows you to uncheck the symantec add-in, but it reloads every time the application is restarted.  For me, this was a dead end.

    The AS workaround worked for me, and the annoyance is gone. One minor exception was that either my typing or some minor syntax error prevented me from deleting it from the command line, as it kept saying it coudln’t find what I wanted deleted.  However, using RegSeeker I searched the registry for "4874559d-e801-4f21-a580-6f5f0b87017c" and it found the offending 3 entries for me, which I confirmed and then deleted.

  3. LTBV01 says:

    Forgot the main reason for posting:

    Thanks for your post/advice, Aaron!  This is the only place I found help.

  4. falcocw says:

    I was having this error and have been researching it on and off for two weeks.  I did the .net uninstall running the MS utility to remove all traces and then reinstalled, which fixed some other issues I was having but not this one.

    I found this post today, and while it has eliminated the ehexthost.exe crash media center now joes loaded into a blank black screen.

    Any suggestions would be welcome, and thanks for this site; it has some excellent information!

  5. Hi Falcocw – I don’t know any reason why removing the registry values described in this blog post would cause Media Center to launch to a black screen.  Usually a black screen means that there is something wrong with DirectX or the video drivers on your system.  I’d suggest trying to search for updated video drivers for your video card and see if that helps resolve this issue.

  6. falcocw says:

    A dxdiag shows

    No problems found.

    DirectDraw test results: All tests were successful.

    Direct3D 7 test results: All tests were successful.

    Direct3D 8 test results: All tests were successful.

    and games such as UT3 run fine.  I have the latest ATI drivers installed for my PCIe HD 2600XT video card.

    Thanks for the reply!

  7. Hi Falcocw – I’m sorry, but I’m not sure what else to suggest.  You could try to put back the registry values that are being removed by the steps listed above in this blog post, but none of those keys would have any effect on whether Media Center appears with a black screen or not to the best of my knowledge, so I don’t really think that it would help at all.

    You may want to try posting a question about this scenario at one of the following locations to see if anyone there can suggest any additional workarounds:

    I’m sorry I haven’t been able to be more helpful in this scenario.

  8. Mike J Kelly says:

    Thanks for this.  Linked to it from for an identical problem I was having, but the error message mentioned SymAddin.  The registry keys are the same and deleting them fixed it.

  9. leemd says:

    Thanks so much!!!!!!!!!!

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