Windows defender-not updating-Engine unavailable

This is what the WD user interface normally looks like. There should not be any Load updates entry and I appreciate that its presence is what you are investigating.
What do you see if you just click on the Virus & threat protection icon itself?


You're getting that update error when you try using the command line to update as well?

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Has that computer ever had another antimalware application on it? If so, was its own specialist removal tool run?
HPs in this country come with McAfee and their tool is called the MCPRTool
Running it even after uninstallation is effective.
How to remove McAfee products from a PC that runs Windows - McAfee support - Use method 2.
Failure to use the specialist tool can have bizarre symptoms. I don't know that this is the cause of your problem but using it will eliminate it as a potential cause and nothing else will.

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In the bottom-left of the user interface there is a Settings entry, click on it then click on About [in the middle of the window] then post your version data.


Here is mine as an example




All the best,
Denis

Okay I'm not expert on this but I'd suggest changing DNS from default ISP provided DNS then swith off computer and reset router.

Boot into windows again and check that the default hosts file is being used (just for now).

Download this script:

ResetWUEng.zip

Then extract it. Switch off router and reboot. (Important)

Or else boot into safe mode without internet.

Reason: There must be no windows update check or background scan for updates in progress and no internet equals no check.

Right click script and run as admin. Choose option 10 then option 11 and finally option 2.

Once complete power off computer. Switch on router and boot into windows. Wait around 5 minutes then go into windows update settings and reconfigure them to your liking. Then if no update check is in progress manually initiate a check.

It should check for updates and download/ install. Of that didn't fix the problem then I don't know how to fix it.

Note: You will loose your (old) update history after running the script but can still view installed updates.

Try3 said:

..........What do you see if you just click on the Virus & threat protection icon itself?.......You're getting that update error when you try using the command line to update as well?.................HPs in this country come with McAfee and their tool is called the MCPRTool. Running it even after uninstallation is effective. How to remove McAfee products from a PC that runs Windows - McAfee support - Use method 2. Failure to use the specialist tool can have bizarre symptoms. I don't know that this is the cause of your problem but using it will eliminate it as a potential cause and nothing else will...........In the bottom-left of the user interface there is a Settings entry, click on it then click on About [in the middle of the window] then post your version data......... Denis

When I click on the Virus and threat protection icon, I get the following screen



Engine unavailable. Clicking on the Check updates button goes through the process of updating with the dotted circle spinning eternally. So I close the window and whatever it takes to shut it down. In the next run, I click on the Check for updates link below the Check for updates button and it takes me to the following screen.



Clicking on the Check for updates button, goes through the process of updating but after a few second stops and takes me back to the Check for updates button. After a few seconds without me doing anything further , this cycle repeats. So again I close down.

I haven't yet tried the command line to update.

I had set up atleast four HP laptops, one for my grand daughter. one for my neighbour, one for my housemaid's son and finally the one for my wife. In all these, the first thing I had done is to remove the pesky McAfee using the McAfee Consumer Product Removal Tool after uninstalling McAfee. I had done it on my present DELL dektop too. All cleanly killed.


Finally here is the screenhot of Settings>about


And @Callender, and @hdmi I shall post for you after a break. May be I have to go to my Bialetti and setup my coffee pot .

Like I said I'm not expert on this but I'm only guessing that some corrupted or missing update is the culprit but it's only a shot in the dark.

I do not recall seeing such a case before.

I think you have already tried SFC.

I think your Version update to 21H2 will not have achieved the same as a Repair install can. A Repair install replaces Windows files whereas, I think, using WU for the update only replaces those files that it has to.

All the best,
Denis

Just a suggestion, as I had a different issue with Defender (no protection history showing), with a laptop preinstalled with McAfee. I'd run the uninstaller then the McAfee removal tool but the issue persisted. It was only after running 'Everything' search (Voidtools) and searching for McAfee that I found a lot of files and registry keys still left. Removed what I found and Defender started working ok.
Might be worth running a search with it?

I've been digging through my notes:-

1 Microsoft Defender AV event IDs and error codes - MSDocs

2 I once used this command successfully when WD stopped updating.
- I think this needs an elevated cmd prompt
- Get the folder info using my post #17
- Run the command MpCmdRun.exe -RemoveDefinitions -All
- You can check the syntax using MpCmdRun.exe /? and Use the command line to manage Windows Defender Antivirus - MSDocs
This command removes all the existing malware definitions so clearing the way for updating to resume.

All the best,
Denis

hdmi said:

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

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.

Do note that the version of RemoveDefinitions you used is not as thorough as the version I suggested in post #28

Best of luck,
Denis