Windows 10: Set-MpPreference -SignatureUpdateInterval 8. This command does not work.

I am trying to follow the steps mentioned below:In the Group Policy Management Editor go to Computer configuration.Click Policies then Administrative templates.Expand the tree to Windows components > Microsoft Defender Antivirus > Signature Intelligence Updates and configure the following settings:a. Double-click the Specify the interval to check for security intelligence updates setting and set the option to Enabled. Enter the number of hours between updates.Instead of manually doing the same, I tried the cmdlet:Set-MpPreference -SignatureUpdateInterval 8gpupdate /forceHowever, this doe

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It seems the the daily (up to 6 times or more a day) windows 10 security updates do not automatically update.

Hi Alan,

The Defender updates are cumulative. By default, Windows Update updates it once per day, although MMPC releases a new set of definitions every 3-4 hours. Other than Windows Update, the Defender signatures are updated by a built-in Defender Update Scheduled task (which is triggered when the system is idle).

To increase the signature update frequency, you can use admin PowerShell and run the following commands:

• set-mppreference -SignatureUpdateInterval 5
  
• set-mppreference -SignatureScheduleDay 0
  

(the above command forces Defender to update its definitions once every 5 hours.)

To revert to the Windows default setting, run:

• set-mppreference -SignatureUpdateInterval 0
  
• set-mppreference -SignatureScheduleDay 8
  

(edited)

 

Windows Security Ignoring Set-MpPreference Settings

For suggestion #1; I have no other antivirus programs installed.

For suggestion #2; I can't use Group Policy Editor as my edition of Windows 10 is Home. The given steps involve disabling Windows Defender completely, which again, I don't want to do. Only the constant background scans.

For suggestion #3; Windows is and constantly is up-to-date with the latest Windows Updates.

For suggestion #4; I'm not sure how this would be any different compared to what I'm currently doing. Powershell has to be elevated in order for the changes to Set-MpPreference to take effect. Otherwise, it will error out. Furthermore, I know that my changes are taking effect (with Powershell elevated) as I can verify them afterwards with Get-MpPreference. Defender just simply refuses to acknowledge the changes and uses the default settings instead.

For suggestion #5; there is no -Default option, so doing Set-MpPreference -Default throws an error.

 

Windows Security Ignoring Set-MpPreference Settings

I'm trying to stop Windows Security from running a daily background scan, which causes my CPU fan to go full throttle continuously for over 40 minutes. Everything that I've changed using the Set-MpPreference command just gets ignored. The changes are reflected when I use the Get-MpPreference command, but Windows Security simply ignores them. I have tried...

• Resetting and re-registering Windows Security through PowerShell.
  
• System File Checker
  
• DISM
  
• Changing related registry settings.
  
• Changing the Task Schedule task, though that gets updated through the Set-MpPreference command.
  
• Changing various Set-MpPreference commands which have made no difference.
  

This has been going on for over 3 months now, and it's not limited to one computer. I have to continuously keep turning off real time protection in order to cancel the background scan, as there is no cancel button. There is obviously something broken between Windows Security and the Set-MpPreference command which causes Windows Security to use its default settings, and I simply don't want (or need) Windows Security running random background scans, especially when real time protection makes scanning pointless.