How to Activate Microsoft Defender in Windows 11
Microsoft Defender is the built-in security tool for Windows 11. It keeps your computer safe from viruses and hackers. If you do not have another security program, you should keep this turned on.
Why: You need it to block harmful software and unauthorized access to your files.
What happens when done: Your computer will be actively monitored for threats and protected by a firewall.
How to Enable Microsoft Defender
You can manage your security settings through the main Windows Settings menu. %%LNK0%%
1. Open the Settings app by pressing Windows key + I on your keyboard or by clicking Start then Settings.

2. In the menu on the left, click Privacy & security. Then, click Windows Security on the right side.

3. Click the Open Windows Security button.

Managing Firewall Settings
In the new window, click Firewall & network protection. You will see three types of networks:
- Domain network: Used for office or business computers.
- Private network: Used for home or trusted work networks.
- Public network: Used for places like airports or coffee shops.
Note: Changing these settings requires admin privileges.
Click on each network profile to turn the firewall on or off.



Managing Virus Protection
1. Click Virus & threat protection in the left menu.
2. Click Manage settings.
3. Toggle Real-time protection and Cloud-delivered protection to the On position.

You can also check App & browser control to ensure your settings are active.

Summary
Microsoft Defender is vital for keeping your Windows 11 PC safe from malware. You should keep it enabled unless you have installed a different security program that conflicts with it. You can manage these settings easily through the Privacy & security section in your Windows Settings. Regularly checking these options ensures your computer stays protected against new threats.
Was this guide helpful?
I get an error saying: “You will need a new app to open this windowsdefender link”. All my options are to open the Microsoft Store which does not give any other options after all.
I have same issue, and i am still searching solution. I found one more thing Windows defender service is stopped and it is not getting started.
Hi .. I can’t open Windows Sercurity .. it doesn’t run any progress … and I don’t see protection arena like pic.2
i have the same problem i can’t open the windows security
This this post.
Enable the service 🙂
Service.msc in the search bar
Find the windows Defender process and enable is click on start and that problem is gone.
Not true. Mine starts and stops immediately thereafter. An sfc /scannow shows no issues. I also have Malwarebytes installed and I know it likes to disable Windows Defender but that should not stop me from enabling it again.
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