Windows 10: Windows 11 - Virus & Protection Engine unavailable

I have seen this issue with Windows 10, but I am running Windows 11, so I am not sure if the fix is the same. The issue started a few months back when I was getting error 0x80070643. Now all I get is Engine Unavailable. I have found lots of suggestions for Windows 10 and tried a few of them, but nothing seems to work.Any ideas?

:)

 

Windows defender-not updating-Engine unavailable

@Try3

Thank you for your quick response. You have always been quick to respond.

This morning I updated the HP laptop to 21H2 through the normal Windows update. Do you still think I should do a repair install with 21H2 ISO?

I am posting three screenshots .













I am yet to try the suggestion made by @hdmi in his post #8

"See also options 2 and 3 in this tutorial:
Windows Defender not updating automatically in Windows 11/10"

I shall try it later tonight and report to hdmi. He must be waiting in the wings.

 

Virus Protection

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If You're Looking For Firewall Protection Then Again, The Free Stuff Come To The Rescue.


1. ZoneAlarm Free
2. Comodo Firewall Pro.
3. PC Tools Firewall

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Windows defender-not updating-Engine unavailable

Option 2: Run the Windows update trouble shooter : Trouleshooter couldn't identify the problem.
The report:





Option 3: Trigger Microsoft Defender using Command line: Failed





When I closely looked at the Security Intelligence updates I observed that the update was downloaded, While installing it the progress indicator jumped from 0 to 33% , remained there for sometime and then jumped to 66% remained at it for sometime and then jumped to 100% but before you can even see it, the the error message pops in.. So I believe the install was also complete but it did not find the engine to attach to, Engine unavailable.
The error message:





Sometimes it is 0x80070643 and sometimes it 0x 80070005.