Windows defender virus definitions update question

I've been using Avast antivirus for a year, and I want to remove it and use Windows Defender, but I'm worried that my Windows Defender won't update its virus definitions because there's an Avast antivirus running. So before I am removing my previous AV and use WD, I want to make sure WD updated to latest version.
Does Windows Defender keep updating its virus definition even though there is another antivirus running on our computer?

With your Avast installed the real-time Defender protection is disabled, but it should still be available for an on-demand scan and should have kept its definitions updated.

You should see definition updates listed in your Update History....



...and in Reliability History.

mikelferdinan said:

I've been using Avast antivirus for a year, and I want to remove it...

for a complete removal you may need to use their removal tool. An uninstall can sometimes leave some things behind.

Avast Uninstall Utility | Download aswClear for Avast Removal

dalchina said:

Normally, yes. Those updates are dependent on certain registry keys/ group policies, and Windows Update running normally.

Should you wish to download the latest updates manually, or see other aspects of this, see:
https://www.microsoft.com/en-us/wdsi/defenderupdates

Bree said:

With your Avast installed the real-time Defender protection is disabled, but it should still be available for an on-demand scan and should have kept its definitions updated.

You should see definition updates listed in your Update History....



...and in Reliability History.

I just check it and look like its dated


Is there a way to update it to latest version?

Bree said:

for a complete removal you may need to use their removal tool. An uninstall can sometimes leave some things behind.

Avast Uninstall Utility | Download aswClear for Avast Removal

I'll try this, thanks.

- - - Updated - - -

I try to run check for updates but there's no update for WD definitions. Do I need to tick the "Receive updates for other microsoft products" ?

mikelferdinan said:

I try to run check for updates but there's no update for WD definitions. Do I need to tick the "Receive updates for other microsoft products" ?

No need to tick 'receive updates for other Microsoft products', Defender is part of Windows and should get updates along with all the other Windows updates.

New definition updates are generally issued several times a day. You have Home, so Windows Update should automatically check once a day and download any new updates. This should happen in the background without notifying you.. To check that it's working go to Settings > Windows Update > Update & Security and click on 'View update history'. Scroll down to where it says...

> Definition Updates

...and click on the > to expand the list. It will tell you the version of the security intelligence update(s) and the date they were installed. At time of writing the current latest definition update on my machine is version 1.323.1647.0.

Bree said:

No need to tick 'receive updates for other Microsoft products', Defender is part of Windows and should get updates along with all the other Windows updates.

New definition updates are generally issued several times a day. You have Home, so Windows Update should automatically check once a day and download any new updates. This should happen in the background without notifying you.. To check that it's working go to Settings > Windows Update > Update & Security and click on 'View update history'. Scroll down to where it says...

> Definition Updates

...and click on the > to expand the list. It will tell you the version of the security intelligence update(s) and the date they were installed. At time of writing the current latest definition update on my machine is version 1.323.1647.0.

I just check it and the last update was 1st march 2020.

I try to run check for updates but there is no update for WD Definition Updates.

dalchina said:

Thank you for your reply.


I have 2 PCs both with Avast installed.
1 regularly updates Defender (I get the WU notifications). The other doesn't.

You can manually update definitions as per my #2.
That link also gives a way to perform a manual Defender update. Did you look at it?

Once you have uninstalled Avast, you could, of course, try performing an in-place upgrade repair install which keeps all progs and data should Defender then still not update.

I can't find a way of repairing Defender otherwise.

The group policy editor shows these options (and more) are available, for which there should be a corresponding registry key:


You have Home so don't have this, but you could try
Policy Plus (free) - a group policy editor with a find option.

Thank you for the reply.

I might not delete Avast because my WD virus definition is outdated. This made me think twice about using WD.
But I also thought that maybe WD will continue updating its virus definitions when I delete Avast. Do you think Avast preventing WD from updating its virus definitions?