Windows Defender will not update its definitions if Windows Updates is not set to Install updates automatically in Windows 11/10/8.1/8. If for some reason you have changed your settings and preferred to set any of the other three updating options, viz. Download updates but let me choose whether to install them, Check for updates but let me choose whether to download and install them or Never check for updates, your Windows Defender will not have the latest definitions, till such a time that you update them manually. This is because Windows Defender and Windows Update are both dependent on the Windows Updates services.
This is not a recommended scenario, as one’s security software should be updated as soon as new definitions are available for download.
Update Windows Defender when Automatic Windows Updates is disabled
But you can set it so that Windows Defender will check for, download and install updates as soon as they are available, even if you have disabled Automatic Windows Updates.
To do so, open the Task Scheduler. You will find it under Administrative Tools in your Control Panel.
In the right pane, click on Create Basic Task. The Create Basic Task Wizard will open. Give the task a name and description and click on Next.
Select the frequency, viz Daily.
Set the Time at which the updating task should run.
Next select Start a program.
In the Program box, type “C:\Program Files\Windows Defender\MpCmdRun.exe”.
MpCmdRun.exe is the executable file of Windows Defender that helps in carrying out common tasks like scanning, scheduling, updating, etc.
In the Add arguments box, type -SignatureUpdate. This is one of the available command line arguments for Windows Defender.
Having done this, review the details and click on Finish.
You will now be able to see the task in the Task Scheduler Library.
Now your Windows Defender will update itself, regularly, every day at the set time, although you may have disabled Automatic Windows Updates.
If you want Windows Defender to check for signature updates more than once every day, you will have to additionally do the following:
Open its Properties box and click on the Triggers tab. Select the task and click on Edit.
Here check the Repeat task every and from the drop-down menu, select 1 hour. This will check for updates every hour. If you wish to check every 6 hours, simply change the figure from 1 to 6; it works!
Click OK/Apply and Exit.
When the task is run, a black CMD window will open momentarily and close down.
If you wish to run a silent update, instead of:
C:\Program Files\Windows Defender\MpCmdRun.exe –SignatureUpdate
you may use:
C:\Program Files\Windows Defender\MSASCui.exe -Update
Let us know how this works for you.
How to schedule Windows Defender scans may also interest you.
Great article!
Under Edit Trigger, it is strange there’s so few drop-down menu items by default.
I noticed when changing to 6 hours, if I type just 6 then click OK and go back in, it assumed I meant 6 minutes. So if I just type ‘6 hours’ it works, showing ‘6 hours’ next next time I go in.
Thank you Anand!
Does this work also in Windows 7?
It would have been helpful if you had included a standard hyphen (“-“) rather than &mdash or whatever that is in front of SignatureUpdate. I copied and pasted to prevent typos, and guess what? I would have been better off typing.
I was able to get Windows Defender definition updates through services.msc. I changed Windows Updates to “automatic”, Windows Defender to “automatic” and another which I don’t seem to remember since I had to refresh my computer. Would you know of this process and how it’s done?
Hey Anand, Thank You for the article, it worked great on Windows 8 as well!!, Thanks Again
Thanks a ton, worked for me on Windows 8.1.
Glad it helped. :)
Excellent article, this is working great for me.
Very useful article.. thanks!
Works as described, although I thought that the ‘silent update’ option would actually be hidden and not noticeable, instead of bringing up and leaving the Windows Defender window. (ironically, the first option seems to just open up a CMD window and promptly closes itself when does, which while a bit rough, it what I was actually looking for)
While I think I can work the CMD option to be fairly invisible, is there any other ways I can have it update without bringing up anything unnecessary?
great, thank you. works on windows 10 too
Thanks for this very helpful article! I didn’t want Windows Update downloading a different build of
Windows10 so I disabled Windows Update in “Services”. Makes no sense when I already have it! Furthermore my Kaspersky Internet Security Suite is incompatible, hopefully for now, with Windows10 and using Defender is the only alternative to buying another security suite that could also be incompatible. Thanks Again!
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Not working for me.
Defining services as automatic has nothing to do with updates being automatic.The two are completely different concepts.
Still wish that Windows provided granular control of what was automatic and what was manual so that Windows Defender can update automatically while other components can download but installation needing to be initiated manually.
Ok, got a working solution:
My task looks like the following:
Action: “C:Program FilesWindows DefenderMpCmdRun.exe” Argument: -SignatureUpdate
Triggers: Workstation unlock (because I use hibernation and want to update the Defender signatures when I get back from sleep – this is just my use case, maybe change it to a fixed time etc.)
General: “Run whether user is logged on or not” + “Do not store password. The task will only have access to local computer resources.” >>> this hides the execution of the task