Windows Defender is turned off or not working

Windows Defender acts as the first line of defense against any sort of malware, spyware infections that might have affected your computer. Microsoft provides this free anti-malware program to customers using Windows. It allows end-users to schedule a scan or manually run a quick, full or custom scan.

Windows Defender

However, sometimes, a user may experience issues enabling Windows Defender application in Windows. He may find that his Windows Defender is turned off or not working. This article explains you the troubleshooting procedure to resolve the same.

Windows Defender is turned off or not working

You may receive a message: Windows Defender has been turned off, and it isn’t monitoring your computer.

If you have another antivirus software installed, it will turn off Windows Defender. But if you do not and yet , then you might want to carry out the following troubleshooting steps:

1] Open Action Center and see if you are able to enable Windows Defender.

2] Run services.msc to open Services Manager. Ensure that the Windows Defender service is started and set to Automatic.

3] Re-register the following dll files and see if it helps you. Run each command in an elevated command prompt one after the other and hit Enter:

regsvr32 wuaueng.dll
regsvr32 wucltui.dll
regsvr32 softpub.dll
regsvr32 wintrust.dll
regsvr32 initpki.dll
regsvr32 wups.dll
regsvr32 wuweb.dll
regsvr32 atl.dll
regsvr32 mssip32.dll

4] It may also happen that Windows Security Center may prompt you to “Check Settings” for the Malware Protection, and when you click the “Turn on now” button, it may show an error that says “There are no new definitions available to download for Windows Defender”

It may be possible that the issue may have been caused due to an inconsistent WMI repository. Restarting the WMI repository should thus help resolve the issue.

Open Command Prompt as an Administrator. Type the following command and hit Enter:

winmgmt /verifyrepository

If you get a message “WMI repository is not consistent”, run the following command:

winmgmt /salvagerepository

cmd

This will perform a consistency check on the WMI repository and resolve the issue. Restart your machine.

Try enabling Windows Defender now.

If you get the following message instead:

winmgmt /salvagerepository is failed

Ignore this message, and again run “winmgmt /salvagerepository”. This time it should help.

This post titled Unable to turn on Windows Defender offers some additional troubleshooting suggestions, which may also interest you.

Read this post if your Antivirus protection has expired.

You may want to also check out these posts which help troubleshoot Windows Defender problems:

  1. Error 0x800106a, Windows Defender will not turn on
  2. Windows Defender Error Code 0x800106ba : Application failed to initialize
  3. Windows Defender Error : MSASCui.exe – Unable To Locate Component.

Updated & Ported from WVC.

Posted by on , in Category Security with Tags
Anand Khanse aka HappyAndyK is an end-user Windows enthusiast, a Microsoft MVP in Windows, since 2006, and the Admin of TheWindowsClub.com. Please create a System Restore Point before trying out any software & be careful about any third-party offers while installing freeware.
  • rajkumar

    first disable third party antivirus restart system and check windows defender services by cntrl+r –type services.msc—-right click on windows defender –property –status type—-select automatic—start services—-then go to control panel –windows defender click on it now it will open and update and scan your computer

  • Johnus Moronus

    I get this message, I have Avira as my antispyware set in Action Center, yet I am only given the option to start or stop Windows Defender, How do I stop the nag at start up?

  • sonofwilliam

    Thank you Mr. Rajkumar for your input on this subject. It would seem apparent then, that Win 8.1 will not run any two AV programs at once? Is that part of this problem? I am also experiencing this on two PCs.

  • hassan mavea

    my windows defender is not opening.. please help me

  • PekkaSteele

    I have Sophos so I just want that annoying window to pop up every time I start my computer. I want to have Windows Defender turned off.

  • Starla Anne Lowry

    Windows defender wants me to scan it 2 or 3 or more times a day. I can scan it and it will tell me to scan it again in a few minutes. That need to be fixed. I have windows 8.1 I have been informed that I cannot delete it and reinstall it.

  • victor c

    In previous windows, Defender had an icon in the system tray. How do I get Windows 10 defender to show on the system tray?

  • Vivek Mallada

    i just upgraded to windows 10 and now it shoes that defender is turned off. if i try to open it to turn it on, it wont open up. i havent installed any third party antivirus. help plz…..

  • Kay Malm

    I receive an access denied even after going to the main folder.

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