Windows Defender won't start in Windows 7 (Error code: 0x800106ba) RRS feed

  • Question

  • I have Windows 7 and Windows Security Essentials installed. Defender has never started automatically, but worked once started. In the last couple of weeks it has failed to initialise on three computers, all returning the error code 0x800106ba.

    The service stubbornly remains on Manual and will not change to Automatic.

    Anyone know what has happened?
    Thursday, March 18, 2010 12:48 AM


All replies

  • Hi,


    If you are running Microsoft Security Essentials, you do not need to run Windows Defender. Microsoft Security Essentials is designed to disable Windows Defender in order to manage the PC’s real-time protection, including anti-virus, rootkits, Trojans and spyware.


    For more information, please refer to:




    If you need more assistance about Microsoft Security Essentials, it is recommended you create a new thread in the Microsoft Security Essentials forum. The support professional there are more familiar with it and can help you in a more efficient way.


    Microsoft Security Essentials Forums





    • Proposed as answer by Meinolf Weber Thursday, March 18, 2010 8:42 AM
    • Marked as answer by Bruce-Liu Friday, March 26, 2010 6:12 AM
    Thursday, March 18, 2010 7:54 AM
  • Thanks for this. Clearly, I don't need Defender as MSE has taken over its function. I guess some recent update disabled Defender which is what brought the matter to my attention.

    Thanks again.
    Thursday, March 18, 2010 1:18 PM
  • Sorry to jump in on this but how do I remove programs from starting at startup without Defender?


    Friday, April 2, 2010 9:46 PM
  • Hi,


    You can use the System Configuration Utility:


    1.    Click Start, click Run, type msconfig, and then click OK.

    2.    Click to the Startup tab and you can clear the box of the program that you want to remove at startup.




    Tuesday, April 6, 2010 9:55 AM
  • Mr. Bruce,

    I realize this is an old post but I'd like to point out that most techs don't consider MSCONFIG to be a permanent solution to controlling programs that start at boot time.  MSCONFIG is most useful for troubleshooting.

    I've read other posts recommending using AUTORUNS from the Microsoft Sysinternals group.  I've used this for several years but it isn't appropriate for the average user.

    It appears that Microsoft doesn't see the need to provide an easy way to control startup programs with Microsoft Security Essentials replacing Windows Defender.  One solution is to buy a more powerful computer to run all that junk.

    Friday, March 4, 2011 6:37 PM
  • Thank you for the help, I am using Microsoft Securtiy Essentials & was trying to turn on Windows Defender, thanks to you I feel alot better. thank you again, Richard Mcfall.......

    Monday, November 21, 2011 6:19 PM
  • thanx bruce...dis had me on my toes fr days..thnk u vry mch...

    Thursday, May 10, 2012 2:54 PM