Error Code 0x800106ba, Windows Defender Application failed to initialize

Why does this problem arise? Well, some third-party software installations cause a conflict with Windows Defender. Running two security software can also create such problems. Sometimes, the DLL files from the utility are not registered properly. They too can cause the problem. To fix this issue, you can try the following:

1] Check Windows Defender service status

Run services.msc to open the Services Manager and ensure that the following Services show this status:

Windows Defender Firewall – Automatic | StartedWindows Defender Advanced Threat Protection – ManualMicrosoft Defender Antivirus Network Inspection Service – ManualMicrosoft Defender Antivirus Service – Manual.

2] Re-register Windows Defender DLL files

We will be telling you how to re-register the Windows Defender DLL files here. Open an elevated Command Prompt window, type “regsvr32 file name” and hit Enter.

You have to re-register each of these dll files. So for each of these files, replace “file name” with each one of these, one after the other and hit Enter: Restart and see if it has helped you. If you wish, you may download and use our portable FixWin to reset Microsoft Defender settings to default.

You will find the setting under AdditionalFixes > Quick Fixes > Reset Windows Defender Settings. You may also see if this Microsoft Fix It 9779673 helps you. Windows Defender is turned off or not working may also interest you.