Windows Update Fails to Update Microsoft Defender

Question

I often get Defender update notifications in Windows Update (see attachment 1) but they always fail to install with error 0x80240017. However, when I immediately check "Protection Update" under "Windows Security", it always shows a newer/updated version (see attachment 2). In this case, Windows Update shows version 1.421.556.0 but Windows Protection Update shows version 1.421.561.0. Also, the Windows Reliability Monitor (attachment 3) shows two update failures both offered by Windows Update. and two update successes I assume that were done automatically. Why does Windows Update offer me Defender updates that always fail but Defender gets updated another way?

Defender Screenshot 1.jpg

Defender Screenshot 3.jpg

Defender Screenshot 2.jpg

Answer 1

You can download the latest updates manually using the methods discussed here:

Security intelligence updates for Microsoft Defender Antivirus and other Microsoft antimalware

Answer 2

Hello,

Error 0x80240017 usually means that the update is not applicable to your system, probably because a newer update is already installed. Windows Security might have already auto-updated the Defender before Windows Update attempted its scheduled check, hence the discrepancy and the failure message.

Try to clear the Windows Update Cache:

Open a Command Prompt as an administrator (right-click on the Command Prompt and select ‘Run as administrator’).

Stop the Windows Update service with the command: net stop wuauserv

Stop the Cryptographic service with the command: net stop cryptSvc

Stop the BITS service with the command: net stop bits

Stop the MSI Installer service with the command: net stop msiserver

Rename the SoftwareDistribution and catroot2 folders to reset the update components. To do this, type the following commands:

ren C:\Windows\SoftwareDistribution SoftwareDistribution.old

ren C:\Windows\System32\catroot2 catroot2.old

Restart the services you previously stopped with the commands:

net start wuauserv

net start cryptSvc

net start bits

net start msiserver

Try running Windows Update again.

Also you could try to manually Install Defender Updates:

You can manually download the latest update for Microsoft Defender Antivirus from the Microsoft Security Intelligence Update page.

Choose the correct version for your system (32-bit or 64-bit) and download the installer.

Run the downloaded file and follow the prompts to update Microsoft Defender manually.

Best Regards,

Hania Lian

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