Q: Windows Defender error 0x800106ba This thread is locked from future replies

Whenever I turn on my computer, a pop-up appears reading:

Application failed to initialize: 0x800106ba. A problem caused this program's service to stop. To start the service, restart your computer or search Help and Support for how to start a service manually.

However, restarting my computer does *not* solve the problem. And, when I was trying to install Windows Defender, it said that I couldn't install it because I have Windows Vista, and Defender is already included. However, I cannot explore Defender on my control panel or through any other shortcut. Furthermore, I tried to uninstall Defender from my "Programs and Features" list, but Windows Defender wasn't even listed. So, does anyone know how I can go about fixing my probelm with Windows Defender?



Hi  re:  Windows Defender error- 0x800106ab ...i have the exact problem that the above (christopherjp) has.

     i read your solution.   i do not have McAfee or Norton. ~please advice. thanx.

1. If you have AVG or Microsoft Security Essentials, Windows Defender will get shut down also.
It is because they have their own defenders. Running 2 defenders in the same machine will create conflicts.
In other word, it is normal to have Windows Defender shut down if you have one of those AV programs installed.

If none of the above applies to you, here is a way to re-start Windows Defender ;

Start button > in the search box, typeServices> press Enter key > scroll to find Windows Defender, click it > ....
under Status heading, it should say ......... Started
under Startup Type, it should say ............ Automatic
If it does not say that, Right click at Windows Defender > click Properties >
at Startup Type, click the pointer at far right and select Automatic
at Service Status, click Start
click OK when done.

For the benefits of others looking for answers, please mark the suggestion as Answered if it solves your problem.

Did this solve your problem?

Sorry this didn't help.

31 people were helped by this reply




are you running any McAfee security product?

"The 2009 McAfee consumer products for Windows Vista disable Microsoft Windows Defender to improve system performance. Windows Vista users who have installed the 2009 McAfee consumer products should not enable Windows Defender..."

Also see the following thread: Windows Defender and McAfee

If still no joy, please contact McAfee Support

If you're running any Symantec/Norton security product instead, see:
"NIS 2009 shutting off Windows Defender"

If still no joy, please contact Norton Support:  
Vincenzo Di Russo
Microsoft® MVP Windows Insider. Internet Explorer, Windows & Security Expert ~ since 2003
Moderator in the Microsoft Community and TechNet Forums

Did this solve your problem?

Sorry this didn't help.

Question Info

Views: 32,384 Last updated: March 19, 2018 Applies to: