Error 0x80070643 - Windows Defender Definition Update Failed - How to Fix

Error 0x80070643 - Windows Defender Definition Update Failed - How to Fix: If you're running Windows 10, you may encounter the Definition Update for Windows Defender - KB2267602 (Definition 1.213.1379.0) - Error 0x80070643". Windows Defender definition updates provide crucial information with regard to known viruses and malware. If the KB2267602 - error 0x80070643 prevents the installation of your definition update on your Windows computers, you need to discern the cause of the error to troubleshoot it.

KB2267602 - error 0x80070643 Cause

Unfortunately, up to the time of writing this article, there is no official word from Microsoft with regard to the cause of the ox80070643 error. Speculation in the Windows community suggests that the error stems from a conflict between Windows Defender and Windows Update. The cause being that both of these applications attempt to download and install the definition update separately but at the same time. Luckily, there exists a simple fix. All you need to do is download the update via the Windows Defender app and you should be error free.

Fix KB2267602 - error 0x80070643

  • Open the Start Menu.
  • Click on Settings.
  • Click on Update & Security.
  • Click on Windows Defender in the left pane.
  • In the right pane, scroll down to the Version info section and click on Open Windows Defender to launch the desktop Windows Defender app.
  • Once in the Windows Defender app, navigate to the Update
  • Click on Update.

Wait for Windows Defender to check for, download and install any and all available Definition Updates. Once Windows Defender downloads & installs the updates you no longer see pending Definition Updates for Windows Defender are reported in Windows Update. Nor do you receive the 0x80070643 error code.

Disable Norton Antivirus

  • Deactivate Norton Smart Firewall and Auto-Protect
  • Reboot
  • Open Windows Defender and turn it on (can't do that when Norton was active and prior to reboot)
  • Run Windows Update -> Defender should install successfully.
  • Reboot.
  • Turn on Norton Smart Firewall & Auto-Protect.
  • If you're using a different antivirus, try disabling it completely and performing the update.


This error, 0x80070643 Windows Defender Definition Update Failed, stems from two possible issues. Your antivirus or your Windows Update/Defender conflict. The steps above help to fix the KB2267602 (Definition 1.213.1379.0) - Error 0x80070643 error. If you have any suggestions or queries then please feel free to leave us a comment and we'd be happy to get back to you. Thanks for reading, FIX Error 0x80070643 - Windows Defender Definition Update here on Orduh! Check out our other guides and Microsoft Windows Guides.

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