8 Solutions to Fix Windows Security Not Opening Issue in Windows

2024/11/20

Windows Security, which encompasses the antivirus program Microsoft Defender, is built to safeguard your PC against viruses and malware. However, like any application in Windows, it can encounter issues, including the situation where Windows Security fails to launch.

1. Repair or Reset Windows Security

Windows 11 provides a built-in repair tool that can detect and automatically resolve minor application-related issues. Windows Security is included in this functionality. Here’s your guide on how to utilize it:

Press Win + I to access settings, then select System from the menu on the left. Click on System components. Locate Windows Security, click the three dots next to it, then choose Advanced options.

Accessing Advanced Options for Windows Security from Settings.

Scroll to the Reset section. Start by selecting Repair to see if it resolves the issue with Windows Security not opening. If that does not work, repeat the process and select Reset, which will remove all associated data and potentially eliminate any corrupted files.

Repairing and resetting Windows Security.

2. Force Windows Security to Open via Task Manager

If Windows Security fails to launch because it didn’t start correctly, you may force it to open using the Task Manager.

Press Ctrl + Shift + Esc to launch the Task Manager. Click on Run new task located near the top center. Enter windowsdefender:, tick the box for Create this task with administrative privileges, and click OK.

Forcing Windows Security to launch through Task Manager.

3. Utilize SFC and DISM Tools

Sometimes, Windows 11 applications, including Windows Security, may stop functioning due to corrupt or modified files. Fortunately, you can leverage the SFC (System File Checker) and DISM (Deployment Image Servicing and Management) tools to identify and repair these files.

Press Win + R, type cmd, and hit Ctrl + Shift + Enter to open the Command Prompt with administrative rights. Note that if your account does not have admin permissions, this step won’t be successful.

Execute the command sfc /scannow and wait as SFC scans your computer.

Once completed, check whether Windows Security opens. If it doesn’t, proceed with DISM. Keep your PC online during this process as DISM may need to download certain files from Microsoft’s servers.

Open Command Prompt with admin rights again and run these commands in succession:

DISM /Online /Cleanup-Image /CheckHealth
DISM /Online /Cleanup-Image /ScanHealth
DISM /Online /Cleanup-Image /RestoreHealth

After finishing, restart your computer and try launching Windows Security again.

4. Disable Background Applications

I frequently notice applications running in the background even when I believe they’ve been closed. These background tasks can interfere with the operation of Windows Security. Stopping non-essential processes and performing a clean boot might be just what your system requires.

Press Win + R, type msconfig, and hit OK. Navigate to the Services tab. Check the Hide all Microsoft services box, then click the Disable all button. Click OK to apply your changes.

Disabling unnecessary services in msconfig.

Open Task Manager by pressing Ctrl + Shift + Esc. Under Startup Apps, disable each enabled application by selecting it and clicking Disable at the top of the window.

I recommend taking a screenshot before this step so you can easily restore any necessary startup applications afterward.

Disabling startup apps in Task Manager to address Windows Security issues.

Restart your computer. It should start without any third-party applications or services that could disrupt Windows Security. If the application opens successfully, a recently installed program may be the culprit—consider uninstalling any new apps to test this hypothesis.

5. Deactivate and Remove Third-Party Security Applications

If you’ve added another antivirus program to your PC, it may be worth uninstalling. Generally, Windows Security only performs scans occasionally when another antivirus is installed, as only one antivirus can run simultaneously on Windows.

Even with a third-party antivirus, Windows Security should function correctly. Open the dashboard for your antivirus and temporarily disable it. If this does not work, proceed to uninstall it by pressing Win + I to open Settings, navigating to Apps -> Installed Apps, clicking the three dots next to your antivirus, and selecting Uninstall.

Depending on your security needs, using Windows Security in conjunction with Microsoft Defender might suffice.

6. Ensure Your Windows Updates Are Current

A minor bug can disrupt Windows Security functionality, but Windows Updates are intended to address these issues. If your system isn’t updating automatically, press Win + I and select Windows Update in the left sidebar. Click on Check for updates to search for any available updates. Install any pending updates and restart your PC.

If you encounter difficulties with Windows Update, consider trying these solutions.

7. Restart the Windows Security Center Service

Although the Windows Security Center Service is supposed to start during every boot, a glitch may prevent it from doing so correctly, resulting in the irritating issue of Windows Security not launching.

Restart this service by pressing Win + R, typing services.msc, and hitting OK.

Scroll down to find Security Center, right-click on it, and select Restart. This option will only be visible if the service is not currently operational.

Restarting the Windows Security Center service.

Once it’s operational again, ensure to enable these Windows Security features to safeguard your PC.

8. Restore Your System to a Previous State

If Windows Security was functioning correctly not too long ago and has suddenly stopped launching, it could be due to a newly installed application, Windows update issues, a virus infection, a corrupted file, or other factors. Fortunately, restoring your system to a prior state might resolve the issue.

Access your latest System Restore point to revert your PC to a time when Windows Security was operating normally.

Press Win + R, enter rstrui, and click OK. Click Next in the System Restore dialog and select a restore point. After making your selection, click Scan for affected programs to identify which programs/apps may be removed and then proceed through the prompts to restore your system.

Windows Security and Microsoft Defender serve to enhance your security, but understanding their roles is beneficial. Additionally, take the time to learn how the firewall within Windows Security functions.

All images by Crystal Crowder