Fix: Microsoft Defender Threat Service has stopped

Windows Defender is a built-in security solution in Windows. It protects your system from malware and other types of harmful threats. This makes Windows Defender your only security against threats if you don't have another antivirus program.

If Windows Defender is not working, your system will be exposed to many vulnerabilities. Usually, when the threat service is stopped, you can click the "Restart" button, but this does not always work. Luckily, we've put together this article to help you solve this problem.

Why did Windows Defender stop working?

The most common reasons why Windows Defender stops working are:

• Conflicting Antivirus Programs - If you use many different antivirus solutions, one of them May cause the Microsoft Defender threat service to stop.
• Organizational Restrictions - If you are using a work or school account, your organization may have enforced Group Policy settings that prevent you from making certain changes.
• Corrupted User Profile – Your current user profile may be corrupted, especially if someone made changes to the registry.
• Virus - It is also possible that a virus infection has taken control of your computer and overwhelmed the Microsoft Defender Threat Service, so it has stopped.

How to restart Windows Threat Service?

Before turning to the complex solutions below, try these basic workarounds:

• Disable or uninstall third-party antivirus software. Make sure to remove all software residue.
• Check for updates. Make sure your computer receives updates from Microsoft through Windows Update.
• Run an anti-malware scan on your computer.
• Run DISM and SFC scans.
• Restart the computer. Restarting can sometimes clear problems caused by software and hardware settings.

1. Restart the Windows Defender service

1. Press the key to openRun the command. WindowsR
2. Type services.msc in the dialog box and click . Enter
3. Navigate to Windows Defender Advanced Threat Protection Service, right-click it, and select Properties.
4. Under "Startup type", click the drop-down menu, select "Automatic", click "Start", then click "Apply" and "OK" to save changes.

2. Disconnect your work/school account

1. Tap the key and click Settings. Windows
2. Click Accounts in the left pane and select Access work and school.
3. Hit the Disconnect button.

3. To fix Microsoft Defender

1. keys, type Powershell in the search bar and select Run as administrator. Windows
2. Type the following command and click: Enter<strong>Get-AppXPackage | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$ ($_.InstallLocation)\AppXManifest.xml"}</strong>
3. Restart the computer and check if the error exists.

4. Reinstall Microsoft Defender

1. Hit the key to openRuncommand. WindowsR
2. Type Registry Editor in the dialog box and click to open Registry Editor. Enter
3. Navigate to the following location: <strong>Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender</strong>
4. Delete the Windows Defender folder and restart your PC.

5. Create a new user account

1. Hit the key to openRuncommand. WindowsR
2. Type netplwiz and press . Enter
3. Click "Add" in the "User Accounts" window.
4. Select "Sign in without a Microsoft account (not recommended)".
5. Click the Local Accounts button.
6. Enter the username and password for the new user account (optional) and a prompt (in case a password is set). Once completed, click Next.
7. Click "Finish" to create a local account.

Expert Tip:

Some PC problems are difficult to solve, especially when they involve corrupted repositories or missing Windows files. If you are having trouble fixing errors, your system may be partially corrupted.
We recommend installing Restoro, a tool that will scan your machine and determine what the fault is.
Click here to download and start repairing.

After logging in to the new profile, test it and check that the Microsoft Defender Threat Service is running smoothly. If so, you can conclude that your previous profile is corrupted and take the necessary steps to repair it.

6. Re-enable Windows Defender

1. Click the Start menu icon, type cmd in the search bar, and then select Run as administrator.
2. Type the following command and click: Enter<strong>REG DELETE "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v DisableAntiSpyware</strong>

7. To remove the Group Policy restriction

1. key, type cmd in the search bar and click Run as administrator. Windows
2. Type the following commands and press after each command: Enter<strong>reg delete "HKCU\Software\Microsoft\ Windows\CurrentVersion\Policies" /f</strong>##reg delete "HKCU\Software\Microsoft\WindowsSelfHost" /f<strong></strong>reg delete "HKCU\Software\ Policies" /f reg delete "HKLM\Software\Microsoft\Policies" /f<strong></strong>reg delete "HKLM\Software\Microsoft\Windows\CurrentVersion\Policies" /f<strong></strong> reg delete "HKLM\Software\Microsoft\Windows\CurrentVersion\WindowsStore\WindowsUpdate" /f<strong></strong>reg delete "HKLM\Software\Microsoft\WindowsSelfHost" /f reg delete "HKLM\Software\Policies" /f<strong></strong>reg delete "HKLM\Software\WOW6432Node\Microsoft\Policies" /f<strong></strong>reg delete " HKLM\Software\WOW6432Node\Microsoft\Windows\CurrentVersion\Policies" /f<strong></strong>reg delete "HKLM\Software\WOW6432Node\Microsoft\Windows\CurrentVersion\WindowsStore\WindowsUpdate" /f <strong></strong>

Deleting the above registry key will disable settings managed by your organization and give you more control over your system. You may get errors when running some of these, but this shouldn't cause alarm as it just means the entries are not on your PC.

If you have tried all of these solutions and none of them seem to work, we recommend performing a system restore. This can help you roll back to a previous point where Windows had no problems.

If you haven't created a restore point yet, try a clean installation of Windows. This should help you restart Windows without problems. For questions like this, it’s important to consider whether Windows 11 requires an antivirus program.

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