How to stop Windows Defender Antivirus from downloading updates

I'm running WIN10 v 1909 and Avast antivirus.

Since the upgrade to WIN10 v 1903, I've been getting an error message telling me Windows Defender Antivirus update(s) have failed and specifically - "..Security Intelligence Update for Windows Defender Antivirus - KB2267602 (Version 1.305.2729.0)...Error 0x80070643...Retry"

I see that Windows Defender Antivirus is turned off. Despite this, WIN10 continues to download Windows Defender updates, it then finds it cannot install the updates because - I'm guessing - the program Windows Defender Antivirus is not running. I think this then generates the above error message.

Would stopping WIN10 seeking the WDA updates stop the error messages being generated and, if so, how can I stop WDA seeking the updates. The WDA registry is protected.

silverfox2019 said:

I see that Windows Defender Antivirus is turned off. Despite this, WIN10 continues to download Windows Defender updates, it then finds it cannot install the updates because - I'm guessing - the program Windows Defender Antivirus is not running. I think this then generates the above error message.

No, Defender does not need to be running in order for Windows Update (not Defender) to download and install the updates. Defender is kept up to date because even if you have another AV installed, you can still run an on-demand scan with Defender (useful as a second opinion, should you have a suspicious file).

I suggest you run the Windows Update Troubleshooter, you may have more update problems besides Defender updates.

Thank you, all.

I will move my question as you suggested.

It's always a compromise as to how much background one gives when asking a question. So I tried to keep it simple.

Actually I've spend a few weeks trying to fix this. I believe my probelm is uncommon. For example, it only affects my Windows Desktop PC but not my - or my wife's - WIN10 laptops.

I have tried many possible solutions, too many to list here, ranging from checking the Windows Update Troibleshooter through to an In-Place Windows 10 upgrade.

- - - Updated - - -

..oh and I cannot run an On Demand scan. WDA is not running. If I turn off my (main) antivirus software (Avast) then Start WDA via Control Panel -> Administartve Tools ->Services Settings - I see WDA starts for only 5 seconds then turns off again.

silverfox2019 said:

..oh and I cannot run an On Demand scan. WDA is not running.

You should not need to turn off any other AV or have WDA real time protection running in order to be able to do an on demand scan. The scan is just a matter of reading files and checking them against the signatures, an on demand scan (Defender, or any other scanner) does not conflict with any resident real time AV.

Can you run an on demand scan from File Explorer's context menu?

(Option One in this tutorial: How to Scan with Windows Defender Antivirus in Windows 10 )

If not, then you a problem that needs investigating. I'd start with running SFC /SCANNOW

Moved from Windows Updates section, as suggested

I'm running WIN10 Home edition v1909 and Avast antivirus.

Since the upgrade to WIN10 v 1903, I've been getting an error message telling me Windows Defender Antivirus update(s) have failed and specifically - "..Security Intelligence Update for Windows Defender Antivirus "WDA" - KB2267602 (Version 1.305.2729.0)...Error 0x80070643...Retry".

Control Panel -> Adminstrative Tools -> Services reporst that WDA is turned off. Despite this, WIN10 continues to download Windows Defender updates, it then finds it cannot install the updates. I'm wondering if that's because WDA is not running and that's why I'm getting the above error message.

Would stopping WIN10 seeking the WDA updates stop the error messages being generated and, if so, how can I stop WDA seeking the updates. The WDA registry is protected.

I have 15 WDA updates showing as failed updates. All other Winodws updates load immediatley, with no problem.

Update:

Actually I've spend a few weeks trying to fix this. I believe my probelm is uncommon. For example, it only affects my Windows Desktop PC but not my - or my wife's - WIN10 laptops.

I have tried many possible solutions, too many to list here, ranging from checking the Windows Update Troibleshooter through to an In-Place Windows 10 upgrade.

I cannot run an On Demand scan using WDA beacause WDA is not running. If I turn off my (main) antivirus software (Avast) then Start WDA via Control Panel -> Administative Tools ->Services Settings - I see WDA starts for only 5 seconds then turns off again

- - - Updated - - -

...is there a way I can stop Windows 10 Home v1909 from trying to update Windows Defender Antivirus

silverfox2019 said:

...is there a way I can stop Windows 10 Home v1909 from trying to update Windows Defender Antivirus

With respect, that is the wrong question. It would just be hiding the symptoms of a deeper problem. Your Defender should be able to run an on-demand scan and to update its definitions, even when its real-time protection is turned off in favour of your Avast.

Jamis,

Yep it's quite likely that I have got corrupted files from the v1903 WIN10 home upgrade. I'd like to postpone WIN10 upgrades for months myself as problems often occur. But I think with WIN10 Home, one can only delay these mandatory upgrades for a month or less. I often feel I am beta testing for Microsoft. I am now resigned to ignoring the error message. It is only a minor irritation anyway.