Windows 10: Windows defender always wants to scan at 3 A.M.

I have set windows defender to scan every Wednesday at 8 A.M., which it does, but it always wants to scan at 3 A.M. every day too. Can some one help me?

:)

 

Windows Defender on Windows 10 -- full scan taking almost 24 hours to be half done

I'm running Windows Defender on a PC with Windows 10. It's a system powerful enough to run Skyrim with three or four other major programs (MS Office) at the same time.

Here's the situation:

5:14 p.m., begin scan, leave computer alone for four hours. From maybe 9:16 p.m. until around 2 a.m., scan and play Skyrim while scan runs, Windows Explorer open, nothing else running. From around 2 a.m. until 8 a.m. computer is unattended, with Defender
supposedly still running the scan, nothing else running. From 8 a.m. until 4:30 p.m., Defender is supposedly scanning while game being played and Internet Explorer is also open.

Defender is still running. It's been going for 23 and a half hours and it's barely half done. That's not good. While it doesn't keep the person from using the computer during the scan, it's not providing information in a timely fashion that might affect
what the user does.

Does Defender actually run in the background? Does it pause the scan when the computer is unattended? Is it necessary for a user to hang around and click the mouse or tap the keyboard to let Defender know it's not alone?

The computer goes to the lock screen if it's not attended, even if the user doesn't sign out. Is this somehow causing Defender to suspend its scan? Still not good.

It's not useful to have a virus program that won't work without constant supervision. How do I make it do its job when the computer is unattended?

 

Windows defender virus threat & detection stops running at 11.00am every day. Anyone help please?

Im not really a smart guy, but im assuming theres a problem/glitch/error/anything wrong with scheduled tasks, idk if this would help, but since it happens always at 11.00 a.m. (is it EXACTLY 11.00 or AROUND 11.00? Im assuming its exactly
11.00 a.m.) try to check the tasks/programs associated with win defender

 

There's a post here that may help you figure the problem out. The post also has some links to tutorials which may help.

Solved Can I schedule scans with Windows Defender? - Windows 10 Forums

 

That thread says this:

But I don't see a way to disable the daily scan...

 

Curious, I was thinking maybe you just missed turning it off somewhere in the config settings, but apparently there's more to it then that. Have a look here & see if this helps any:

Windows Defender - Turn On or Off in Windows 10 - Windows 10 Forums

 

I don't want to turn it off, I just want to stop the daily scan.

 

I found a way to remove the built in scheduled task for the Daily WD scan.
That was a while ago, with an Insider preview build.
These changes are done in Group Policy (i have W10 Pro).
See this post, maybe this will still work:
Solved Build 10074 Windows Defender scheduled task scans ? - Windows 10 Forums

You might also be able to change some Group Policy settings as you prefer and keep the built in Scheduled Task ?

If you want to get rid of the built in task and create your own scheduled task, an easy way is to export the built in task, then import it as a new task and change the settings to what you want.

 

I thought you might find some information relevant to your problem on that tutorial. Either that, or turning it off & on might solve the problem.

Looks like DavidE has something you can try, hopefully this fixes your problem.

 

Borg, You got me curious about this so i tested the GPO changes with the current official W10 build (not as an insider).
The changes do remove the WD built in daily scheduled scan task. *Party
I'll check tomorrow and make sure W10 didn't rebuild the default task.

Personally i don't think a daily scan is needed for how i use a PC. *Wink

imho it should be easier than this to control scheduled AV scans *Zip

 

Great find David. *Thumbs. I had a scheduling prob with some prog (sorry, can't remember which one) on Win 7 a few years back & found turning it all the way off/back on fixed it for me.

Thanks for investigating.

 

You're welcome and thank you for the added info.
I got even more curious so i made some GPO changes to try and get the default scan to only run once per week.

As usual I'm on the wrong system for this post, I'm on Win 7 right now *Tongue
When i get back on W10, I'll see how things look.

 

I have Home version. So no group policy editor.

I went here: Group Policy Search
and found this.

Policy Configure local setting override for scheduled scan time
Category Path Computer Configuration\Administrative Templates\Windows Components\Windows defender\Scan\
Supported On At least Windows Server 2012, Windows 8 or Windows RT

Registry Key HKLM\Software\Policies\Microsoft\Windows defender\Scan
Value LocalSettingOverrideScheduleTime
Admx WindowsDefender.admx


Explanation

This policy setting configures a local override for the configuration of scheduled scan time. This setting can only be set by Group Policy.

If you enable this setting, the local preference setting will take priority over Group Policy.

If you disable or do not configure this setting, Group Policy will take priority over the local preference setting.

=== Detailed values: ===

Enabled Value:
decimal: 1

Disabled Value:
decimal: 0


But the only thing there is a HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Policy Manager

No HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender\Scan

 

I don't know if you can disable the built in WD scan if you don't have the Group Policy Editor (W10 Pro or Ent)?

When I set day of the week to run a scheduled scan to Never, and set the interval to run quick scans per day to 0 in Group Policy, it immediately deletes the built in WD Scan scheduled task, and updates the registry.

Here is what I see in Regedit after making these changes.





I tried to make changes so it would only run a scan once a week with the built in scheduled task, but that didn't work for me.

 

I just turned Windows Defender back on after uninstalling the bulky Avast. Regarding the 3am auto-scan, does Microsoft assume that most P.C. users leave their computers running, 24/7? I don't.

Speaking of running, my Windows Defender quick scan auto-started after I turned Defender it back on this evening. It's been scanning now for just over 30 minutes and looks to be about 80% done. This is a "quick" scan? *Shock