7 Best Ways To Fix Windows Defender Not Activating Error

Windows Defender has come a long way over the years and is currently one of the best antivirus products. It’s completely free and comes preinstalled on all Windows installations. Most users have nothing to do. However, some of you are having trouble. Windows Defender won’t activate for you.


Fix Windows Defender Do Not Activate Error

Note that Windows Defender was renamed Microsoft Defender in early 2019 and is now part of a larger security product called Windows Security.

It makes little sense to download / buy a third-party antivirus app when the default one is solid and does the job. I suggest you stick with Microsoft Defender. We will help you troubleshoot and resolve the issue in this guide. It is better to let Microsoft spy on you rather than another company. After all, anti-virus applications have system-level access. Microsoft probably already knows everything you do on Windows. What is there to hide?

I guess you’ve already tried checking for updates and restarting your computer once before coming here.

Let’s start.

1. Change of name

Did you skip the opening? You’re not alone. However, they contain important general information on the subject. As previously reported, Windows Defender has been renamed and is now part of Windows Security.

Fix Windows Defender Not Activating Error 1

Fix Windows Defender not activating error 1

You may have looked for the wrong program, thinking it didn’t work. It is but only under a new name. Check again in Task Manager (Ctrl + Shift + Esc).

2. Third-party antivirus

Using a third-party antivirus application will automatically disable Microsoft Defender. The error code for the same is 577, but you may or may not witness it. A bit unnecessary to run two antivirus applications on the same machine at the same time. Turn off one to turn on the other. Uninstall it if you want to use Defender.

Fix Windows Defender Not Activating Error 2

Fix Windows Defender Not Activating Error 2

Some applications like Malwarebytes allow both applications to run simultaneously. We recommend this setup and I use both. Check if you can activate it manually under “Virus and threat protection”.

3. Check for errors

System File Checker or SFC Scan will find and repair corrupt or missing system and registry files which are crucial for running basic applications like Defender.

Step 1: Find and open the command prompt from the Start menu with administrator rights. You can also use PowerShell, which is more advanced.

Fix Windows Defender Not Activating Error 3

Fix Windows Defender Not Activating Error 3

2nd step: Give the commands below, one at a time, and wait for it to run. A restart is recommended.

sfc /scannow

and

DISM /Online /Cleanup-Image /RestoreHealth
Fix Windows Defender Not Activating Error 4

Fix Windows Defender Not Activating Error 4

6. Microsoft Defender Service

Ideally, the Microsoft Defender service should be configured to run automatically when the computer starts up. In your case, it could be incorrectly adjusted, requiring manual intervention.

Step 1: Find and open the services from the Start menu with administrator rights.

Fix Windows Defender Not Activating Error 8

Fix Windows Defender Not Activating Error 8

2nd step: Find and double-click Microsoft Defender Antivirus Service in the list.

Fix Windows Defender Not Activating Error 9

Fix Windows Defender Not Activating Error 9

Step 3:
The start type should be set to Automatic and the service status should be Running. Otherwise, click the Start button below to start it. Save the changes and restart to check again if Windows / Microsoft Defender is automatically turned on or off.

Fix Windows Defender Not Activating Error 10

Fix Windows Defender Not Activating Error 10

In my case, it shows up as Stopped because I am using Malwarebytes while Microsoft Defender is configured for periodic scans instead of real time. You have another antivirus product installed and running if the options are grayed out here.

7. Clean boot

We have written a detailed guide on this topic. What it will do is help you find that app that could be responsible for breaking Defender’s functionality. A possible conflict.

Reigning champion

Microsoft Defender has made a successful comeback in recent years and has a new home. Windows security offers many more ways to protect your computer than just virus scans. Take the time to go through different options and learn what they do. Antivirus apps are infamous for slowing down Windows, which is just another reason to use Defender.

What do you think? Have a suggestion or a solution that we missed? Share it in the comments section below for everyone. Be a good samaritan.

Then:

Want to completely disable Microsoft Defender on your computer? Click the link below to find out how but don’t forget to install a better antivirus.

Last updated Sep 7, 2020

The above article may contain affiliate links that help support Guiding Tech. However, this does not affect our editorial integrity. The content remains impartial and authentic.

(function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(d.getElementById(id))return;js=d.createElement(s);js.id=id;js.src=”http://connect.facebook.net/en_US/sdk.js#xfbml=1&version=v2.5&appId=1652915528311925″;fjs.parentNode.insertBefore(js,fjs);}(document,’script’,’facebook-jssdk’)); .

Leave a Reply