SOLVED Windows 10 won't update Defender definitions.

[David49]

Hello. My Windows 10 system will not update virus definitions.

I have tried triggering an update manually.
I have tried to get this to update from the security page.
I've tried from a command prompt.
I have tried downloading the update and run it manually.
All run as administrator.

It always tells me no action is necessary and I'm up to date. Nothing I tried works.
I'm still showing the last update was on 11/10/2020. And I know there are updates daily.

Oh yeah, other updates are detected just fine.

Cumulative updates download and install just fine.
As does the malicious software removal tool.

Strangely, the virus defs run just fine right after any one of the other updates installs.
But then in a few days it starts all over again with the Defender not updating again.
I'm out of ideas. Anyone know what's going on?

 

[Tim Locke]

Defender is running? It isn't being prevented from running by some other AV product? I just checked at 19:39 EST and got an update to defender.

 

[David49]

I also have Malwarebytes running. They are both in the sys tray. They have never conflicted before. I have been updating Defender for years along with MB. I suppose I suppose I could disable MB and see if Defender will update.

 

[David49]

I just disabled MB, and Defender updated manually just like it always used to. Good call. Now, I have to somehow discover why this is happening all of a sudden. Thanks very much for your insight.

 

[Bastet]

Is Malwarebytes the Premium/full version or free?
If premium then this has a register with security centre option which disables Defender. This should really be off so both programs work together.
If free then ensure Defender isn’t on the blocked list.

 

[David49]

I have the Premium version. The trouble is that I think this machine is lying to me. I see that Defender says it is on and no action is needed. It is in my systray with a green check mark on the icon. And when I force an update manually, there is a search-like pause after which it says my machine is up to date.

 

[Bastet]

Check Malwarebytes for that setting.
Add these folders to MB exclusion list:

Exclusions for Windows Defender users.

Add to Malwarebytes Exclusions the following folders. C:\Program Files\Windows Defender C:\Program Files (x86)\Windows Defender C:\ProgramData\Microsoft\Windows Defender (Enable hidden files to add this one.) For Win 10 PRO only also add these Folders. C:\Program Files\Windows Defender Advanced T...

forums.malwarebytes.com

Also ensure MB is up to date.

 

[David49]

Is the Allow List the same as the Exclusions? Because when I try to add these folders, the folder just opens and shows me it's contents.

 

[Bastet]

Yes.
There should be an option to add entries. If not then I’ll supply a screenshot of what I see within MalwareBytes.

 

[David49]

Yes.
There should be an option to add entries. If not then I’ll supply a screenshot of what I see within MalwareBytes.

Please supply screenshot.

 

[Bastet]

Screenshots.

 

[David49]

Ok. Does this look correct to you?

 

[Bastet]

Yes, that looks fine.

 

[David49]

Yes, that looks fine.

Cool. Now I wait to see if the defs will update. The last one was installed yesterday. 11/21/2020 So, I should have another one tomorrow...maybe.

 

[Bastet]

There’s usually at least one a day so I’d try to check for any updates manually.

 

[David49]

There’s usually at least one a day so I’d try to check for any updates manually.

Yes. I have rebooted and then manually checked for any updates. None so far. I am "up to date" as usual. I'll keep checking. Thanks for all your help.

 

[Bastet]

Keep us posted.

 

[David49]

Keep us posted.

I will.

 

[David49]

My most recent update attempt a few minutes ago:

 

[David49]

I tried it again a few minutes ago. Looks like success. The second image is to show you what else I did besides what you said I should do. I turned off "Always Register MB in Windows Security Center". The first image is the successful update of definitions.