Windows 11 Defender not installed? Here’s how to solve it

by Ola-Hassan Bolaji
Ola-Hassan Bolaji
Ola-Hassan Bolaji
A Computer Engineering graduate, he has spent most of his life reading and writing about computers. Away from computers, he is either reading or watching football! read more
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  • Windows Defender has seen some major security improvements in Windows 11.
  • However, some users find the app missing after updating their new OS.
  • To start resolving this issue, reinstalling the app with PowerShell will most likely do the trick.

ESET Antivirus comes with all the security tools that you may ever need to protect your data and privacy, including:

  • Anti-theft support
  • Webcam protection
  • Intuitive setup and UI
  • Multi-platform support
  • Banking-level encryption
  • Low system requirements
  • Advanced anti-malware protection

An antivirus program needs to be fast, efficient, and cost-effective, and this one has them all.

Windows 11 Defender not installed is one of the numerous problems users face trying to use Microsoft’s default antivirus on their PC.

In the past, users have complained that Windows 11 Defender is turned off. But some could not even find the app on their PC at all.

Thankfully, the fixes for this problem are not far-fetched, with just a little tweak here and there needed in most cases.

In this guide, you will learn four practical ways to solve the problem and return normalcy to your PC. Better still, you can save yourself all the troubles and errors with a better alternative in ESET antivirus software.

What does Windows Defender do on Windows 11?

Since the days of Windows Vista, Windows Defender has always been the default windows antivirus software.

It has seen some major and encouraging improvements over the years. It has metamorphosed from just offering limited protection to being one of the best free antivirus software available.

Unlike the early versions of Windows Defender, the latest release on Windows 11 offers complete malware and ransomware protection.

This is more than some paid antivirus software offers. It is safe to say that the Windows Defender software keeps your PC protected from viruses in real-time.

How is Windows Security different from Windows Defender?

Microsoft’s default antivirus and security app on PC was initially Microsoft Security Essentials.

The name changed to Windows Defender in Windows 7 and later Windows Security in Windows 10.

The name has been maintained in Windows 11 but with some improved features. Hence, Windows Defender and Windows Security are the same with just the evolution of names over time.

Ways to Solve Windows 11 Defender not installed

1. Install Using PowerShell

  1. Right-click on the Start icon in the Taskbar.
  2. Select the Windows 11 Terminal (Admin) option to open
  3. Click the Yes button to allow PowerShell to make changes to your PC.
  4. Type the following commands: Set-ExecutionPolicy Unrestricted
    Get-AppXPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}. powershell install windows 11 defender
  1. Now, press the Enter key and let the command run.

The command above helps to reinstall all default Windows apps. This is especially useful if Windows 11 Defender is not installed due to file corruption during an upgrade.

2. Repair and reinstall

  1. Right-click on the Start icon on the Taskbar and select the Windows Terminal (Admin) option.
  2. Type the command: Get-AppxPackage Microsoft.SecHealthUI-AllUsers | Reset-AppxPackagerepair and reinstall windows 11 defender
  3. Now, press the Enter key and allow the command to run.

Sometimes, Windows 11 Defender might be installed but installed incorrectly or incompletely.

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The command above will remove all components of Windows Security on your PC. After this, it will help you reinstall a compatible version.

3. Perform Windows update

  1. Press the Start button.settings windows 11 defender not installed
  2. Click the Settings 11 update defender not installed
  3. Select the Windows Update option on the left pane.check for update windows 11 defender
  4. Click the Check for updates button in the right pane.

Windows update comes with fixes for bugs and other errors in the previous versions.

If Windows 11 Defender is not installed on your current version of OS, an update should have fixes to the bugs that could have caused it. Also, if it is due to an incomplete or incorrect update, this should solve the problem if done properly.

4. Perform system Restore

  1. Click the Windows icon and type system restore.
  2. Choose the Create a restore point option.system restore windows 11 defender
  3. Click the System Restore system restore windows 11 defender
  4. Select Next in the System Restore window to proceed.restore point windows 11 not installed
  5. Choose a restore point from the options provided.
  6. Now, click the next button and follow the onscreen instructions to finish the restoration.

If you noticed Windows 11 Defender missing after installing an update, this fix could help you return to normal service. Just select a later restore point before installing the new update, and things should get back to normal.

Is Windows Defender enough for my PC?

As mentioned earlier, the Windows Defender has come a long way since they were first released with Windows Vista.

It has become very effective in detecting and eliminating malware and ransomware. It has upped the ante with sandboxing and cloud-based malware detection and blocking network-based.

Also, it flags phishing websites among the impressive features of this new Defender on Windows 11.

However, Microsoft is not a cybersecurity firm, and there is room for improvement. Dedicated PC and data protection software offers more complete features than the Defender.

They offer full PC security against even the most stubborn malware and online data security. They also provide advanced data security like data encryption, among other amazing features.

Impressively, it does not have to be one or the other as most can work on the same PC with Windows Defender.

The Windows 11 Defender not installed problem is not the first to be faced by users. There have been complaints that Windows 11 Defender is not opening or not enabled, among other issues.

Unlike some of these issues, this problem is not hard to fix, as we have shown above. We hope you find the guide useful and get Windows Defender back to protect your PC.

Feel free to discuss the solution that worked for you in the comments section. You can also state any solution you tried successfully that is not in this guide.

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