Windows Defender Error code: 0x80070426

When my PC starts I get this error code and windows defender will not start.

I tried sfc /scannow it said it found some issues but cannot repair them all, I also tried repairing under safe mode.

This happened after upgrading to build 1607


We understand that you get the error code, 0x80070426  when you try to use the Windows defender. Also that the SFC scan was unable to fix it even in the safe mode. That being said, please try to do a DISM scan and check if it helps. Ensure that the computer is connected to the internet when you do so.

Deployment Image Servicing and Management (DISM) is a new command line tool that you can use to service a Windows image or prepare a Windows PE image. The DISM tool replaces the Package Manager (pkgmgr.exe), PEimg, and Intlcfg tools. DISM consolidates the functionality found in those three tools, as well as delivers new functionality to improve the experience of offline servicing.


Please follow the given steps to run a DISM scan:


1) Press Windows + x on your keyboard.


2) Select Command prompt (Admin) to open Administrator Command prompt.


3) In the Administrator: Command Prompt window, type the following commands. Press the Enter key after each command:

dism.exe /online /cleanup-image /scanhealth


     dism.exe /online /cleanup-image /restorehealth

If the issue still persists, please try to run a clean boot and check if it helps.

Putting your system inClean Boot state helps in identifying if any third party applications or startup items are causing the issue. You need to follow the steps from the article mentioned below to perform a Clean Boot.


DISCLAIMER: After troubleshooting, refer to this section “How to reset the computer to start normally after clean boot troubleshooting”.

Please get back to us with the necessary details so that we can resolve your issue at the earliest.

Thank you.

Have a good day!

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