Fix: Windows Defender will not update definitions

If your Windows Defender will not update or if you ever encounter an error code (eg. Error code 0x80240029 – Cannot update Windows Defender), when updating this free antivirus software from Microsoft, here is a solution which may help you. 

Windows Defender

Windows Defender will not update

This usually happens if the distribution database is broken and needs to be re-created.

Typically you may get an error message: Error found: Code error_code

  • The program can’t check for definition updates
  • The program can’t download definition updates
  • The program can’t install definition updates

And the error_code could be:

  • 0x8024402c
  • 0x80240022
  • 0X80004002
  • 0x80070422
  • 0x80072efd
  • 0x80070005
  • 0x80072f78
  • 0x80072ee2
  • 0x8007001B

To address the issue you may try these troubleshooting steps :

1] Switch from Microsoft Update to using Windows Update. As far as Windows 8, Windows 7 or Windows Vista goes, you can do this by clicking open Control Panel  > Windows Updates> Change settings > Uncheck Automatic Updates, Uncheck Recommended Updates and Uncheck use Microsoft Update Service. This will switch from Microsoft Update back to using Windows Update. Reboot. If it works for you fine; you can now reset the update settings to as they were earlier.

2] Run the Windows Update Troubleshooter from Microsoft. Check this Fix It to reset Windows Update components and this Fix It to repair Windows Update components. Please check which Fix It applies to your version of Windows.

3] Update Windows Defender manually. To manually download the latest definition updates for Windows Defender:

Windows Defender in Windows 8 32-bit         |          64-bit         |          ARM
Windows Defender in Windows 7, Vista, XP 32-bit         |          64-bit

Save it to your desktop. ‘Run As Administrator’ this mpasfe.exe,

When the definition file runs, a file extraction dialog box appears. After the file extraction dialog box closes, verify that the Windows Defender definitions have been updated.

4] Use a standalone anti-malware to scan your system for malware. Sometimes malware can turn off updating of security software.

5] Open Task Manager, and terminate the Antimalware Service Executable or msmpeng.exe process. Now open Control Panel and run Windows Update and see if this works.

6] Lastly if nothing works, there is one thing you can try: Boot into Safe Mode. Find the folder named Software Distribution.  Rename SoftwareDistribution to SoftwareDistribution.old OR delete all its contents. Reboot. Now try to update the Defender. At this point a new Software Distribution folder will be created if you have renamed it.

Hope something helps.

Posted by on , in Category Security with Tags

Anand Khanse is the Admin of TheWindowsClub.com, a 10-year Microsoft MVP Awardee in Windows (2006-16) & a Windows Insider MVP. Please read the entire post & the comments first, create a System Restore Point before making any changes to your system & be careful about any 3rd-party offers while installing freeware.