Windows Defender will not update definitions
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 updatesThe program can’t download definition updatesThe program can’t install definition updates
And the error_code could be:
0x8024402c0x802400220X800040020x800704220x80072efd0x800700050x80072f780x80072ee20x8007001B
Protection definition update failed
To address the issue, you may try these troubleshooting steps :
1] Run the Windows Update Troubleshooter
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.
2] Manually download the latest definition updates
Update Windows Defender manually. To manually download the latest definition updates for Windows Defender:
Download definition updates for Windows Defender in Windows 10, Windows 8.1: 32-bit | 64-bit | ARM.
Other links: Save it to your desktop. ‘Run As Administrator’ this mpas–fe.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.
3] Scan your system for malware
Use a standalone anti-malware to scan your system for malware. Sometimes malware can turn off updating of security software.
4] Terminate msmpeng.exe process
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.
5] Check Service status
Open Services Manager, locate Windows Defender Antivirus Service, right-click on it and select Restart. Check its Properties. It should be set to start Automatically.
6] Switch from Microsoft Update to using Windows Update
Switch from Microsoft Update to using Windows Update. As far as Windows 8/7/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.
7] Clear Software Distribution folder contents
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.
