How to Fix Windows Security Not Working in Windows 11

Windows Security is the built-in security suite in Windows 11 that provides real-time protection against viruses, malware, ransomware, and other threats. It includes features such as Virus & Threat Protection, Firewall & Network Protection, Device Security, and App & Browser Control. When Windows Security stops working, it may fail to open, display a blank screen, show “Security at a glance” errors, or report that the service is disabled.

Windows Security not working in Windows 11 is typically caused by corrupted system files, disabled security services, third-party antivirus conflicts, Windows update issues, or damaged application components. Since Windows Security is deeply integrated into the operating system, resolving the issue requires checking services, system integrity, and update status.

This guide explains how to fix Windows Security not working in Windows 11 using structured troubleshooting steps.

How to Fix Windows Security Not Working in Windows 11

Follow the solutions below in order until Windows Security functions properly.

1. Restart Your Computer

Temporary glitches may prevent Windows Security from launching.

1. Close all open applications.
2. Click Start.
3. Select Power.
4. Click Restart.
5. After rebooting, open Windows Security again.

A restart refreshes background services and security components.

2. Check Windows Security Services

Essential security services must be running.

1. Press Windows + R, type services.msc, and press Enter.
2. Locate Security Center.
3. Right-click it and select Properties.
4. Ensure Startup type is set to Automatic (Delayed Start).
5. Click Start if the service is not running.
6. Repeat the same steps for Windows Defender Antivirus Service.

Restart your PC after making changes.

3. Remove Third-Party Antivirus Software

Third-party antivirus programs may disable Windows Security.

1. Press Windows + I to open Settings.
2. Click Apps, then select Installed apps.
3. Locate any third-party antivirus software.
4. Click Uninstall and follow the prompts.
5. Restart your computer.

After removal, Windows Security should reactivate automatically.

4. Reset Windows Security App

Corrupted app data may prevent it from opening.

1. Press Windows + I to open Settings.
2. Click Apps, then select Installed apps.
3. Locate Windows Security.
4. Click the three-dot menu and select Advanced options.
5. Click Repair first.
6. If the issue persists, click Reset.
7. Restart your PC.

Resetting restores default settings.

5. Run System File Checker (SFC)

Corrupted system files may affect security components.

1. Press Windows + S, type cmd.
2. Right-click Command Prompt and select Run as administrator.
3. Type the following command and press Enter:sfc /scannow
4. Wait for the scan to complete.
5. Restart your computer.

SFC repairs damaged Windows system files.

6. Run DISM to Repair System Image

If SFC does not resolve the issue:

1. Open Command Prompt as administrator.
2. Type the following command and press Enter:DISM /Online /Cleanup-Image /RestoreHealth
3. Wait for the process to finish.
4. Restart your PC.

DISM repairs deeper system corruption.

7. Install Windows Updates

Outdated system builds may contain security-related bugs.

1. Press Windows + I to open Settings.
2. Click Windows Update.
3. Select Check for updates.
4. Install all available updates.
5. Restart your computer.

Updates often include security improvements and bug fixes.

8. Re-register Windows Security App

If the app is missing or corrupted:

1. Press Windows + S, type Windows PowerShell.
2. Right-click it and select Run as administrator.
3. Enter the following command and press Enter:Get-AppxPackage Microsoft.SecHealthUI -AllUsers | Reset-AppxPackage
4. Restart your PC.

Re-registering restores the Windows Security interface.

9. Check Group Policy Settings (Windows 11 Pro)

Policies may disable Windows Defender.

1. Press Windows + R.
2. Type gpedit.msc and press Enter.
3. Navigate to Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus.
4. Ensure Turn off Microsoft Defender Antivirus is set to Not configured.
5. Restart your PC.

Correct policy settings ensure Defender is enabled.

Conclusion

Windows Security not working in Windows 11 is typically caused by disabled services, third-party antivirus conflicts, corrupted system files, Windows update issues, or damaged app components. By restarting services, removing conflicting software, repairing or resetting the app, running SFC and DISM scans, installing updates, and verifying policy settings, you can restore full security functionality.