How to Fix MRT Not Working in Windows 11

The Microsoft Malicious Software Removal Tool (MRT) is a built-in security utility that helps detect and remove specific widespread malware from your system. It usually runs silently in the background after Windows Updates, but you can also launch it manually. However, many users report that MRT does not open, closes immediately, or doesn’t run at all on Windows 11.

If MRT is not working on your system, the issue is typically related to Windows Update problems, disabled services, corrupted system files, or policy restrictions—not malware blocking the tool. This guide walks you through all reliable fixes, step by step.

What Is MRT and How It Normally Works

• MRT is included with Windows via Windows Update
• It runs automatically once per month after Patch Tuesday
• The executable is mrt.exe, located in C:\Windows\System32
• It is not a real-time antivirus (that role belongs to Windows Security)

If MRT is missing or won’t launch, something is blocking its execution.

Why MRT Is Not Working in Windows 11

Common causes include:

• Corrupted or missing mrt.exe
• Windows Update components not working
• Disabled Windows Update or related services
• Group Policy restrictions
• Corrupted system files
• Outdated Windows build
• Third-party security software interference

Fix MRT Not Working in Windows 11

Follow the steps below in order. After each step, try running MRT again.

1. Run MRT Manually the Correct Way

First, make sure you’re launching it properly.

1. Press Windows + R.
2. Type: mrt
3. Press Enter.

If MRT opens, choose Quick scan to test functionality.

2. Check If MRT Exists on Your System

Sometimes MRT is missing entirely.

1. Open File Explorer.
2. Navigate to: C:\Windows\System32
3. Look for mrt.exe.

• If it’s missing, jump to Step 5
• If it’s present but won’t open, continue below

3. Run MRT as Administrator

Permissions can block execution.

1. Go to: C:\Windows\System32
2. Right-click mrt.exe.
3. Select Run as administrator.

If it works this way, a permission or policy issue is likely.

4. Check Group Policy Restrictions (Pro & Higher)

MRT can be disabled by policy.

1. Press Windows + R, type gpedit.msc, and press Enter.
2. Navigate to: Computer Configuration → Administrative Templates → Windows Components → Microsoft Malicious Software Removal Tool
3. Open Turn off the Microsoft Malicious Software Removal Tool.
4. Make sure it is set to Not Configured or Disabled.
5. Restart your PC.

If it’s set to Enabled, MRT will not run.

5. Install or Reinstall MRT via Windows Update (Most Important Fix)

MRT is delivered through Windows Update.

1. Open Settings → Windows Update.
2. Click Check for updates.
3. Install all available updates, including cumulative updates.
4. Restart your PC.

If MRT was missing, Windows Update will reinstall it automatically.

6. Restart Required Windows Services

MRT depends on update-related services.

1. Press Windows + R, type services.msc, and press Enter.
2. Make sure these services are Running and set to Automatic:
   • Windows Update
   • Background Intelligent Transfer Service (BITS)
   • Windows Installer
3. Restart these services if needed.

Now try running MRT again.

7. Run System File Checker (SFC)

Corrupted system files can prevent MRT from launching.

1. Open Command Prompt (Admin).
2. Run: sfc /scannow
3. Wait for the scan to finish.
4. Restart your PC.

If SFC repairs files, MRT usually starts working again.

8. Repair Windows Image Using DISM

If SFC is not enough, DISM fixes deeper issues.

1. Open Command Prompt (Admin).
2. Run: DISM /Online /Cleanup-Image /RestoreHealth
3. Let the process complete fully.
4. Restart Windows.

This repairs the component store MRT relies on.

9. Temporarily Disable Third-Party Antivirus

Some security tools block MRT by mistake.

1. Temporarily disable third-party antivirus software.
2. Run mrt.exe again.
3. If it works, add MRT to the antivirus exclusion list.

Do not leave your system unprotected—re-enable security afterward.

10. Download and Run MRT Manually (Safe Method)

If Windows Update doesn’t restore it:

1. Download the latest Microsoft Malicious Software Removal Tool directly from Microsoft.
2. Run the downloaded executable as administrator.
3. Complete a scan.

This version is identical to the Windows Update-delivered one.

Wrapping Up

If MRT is not working in Windows 11, the problem is usually caused by Windows Update issues, disabled policies, or corrupted system files, not malware interference. By checking Group Policy, reinstalling MRT via Windows Update, repairing system files with SFC and DISM, and ensuring required services are running, you can restore MRT in most cases.

Once fixed, MRT will continue doing its job quietly in the background—adding an extra layer of protection to your Windows 11 system.