“Windows Security threat service has stopped restart it now” is a common issue. If you are hit by this unexpected error in Windows 10/11, what should you do to get out of the trouble? Take it easy and you can find some effective solutions from this post on the MiniTool website.

Threat Service Has Stopped Restart It Now Windows 10/11

Windows Defender, also called Windows Security, is a powerful antivirus program that is built in Windows 10 and 11. It can help to scan the entire operating system and protect the PC against malware and viruses in real-time.

However, sometimes this antivirus software doesn’t function properly and you may run into some common issues, for example, Windows Defender not turning on , Windows Security not working , Windows Defender Offline Scan not working , and more. If you encounter one of these issues, click the given link to find solutions.

Besides, you may be hit by another common unexpected error - threat service has stopped restart it now. This is the topic that we will discuss today.

When trying to launch this antivirus program, you may see this error message. If you click the Restart now button, the service starts and the error disappears. That’s good. However, if not, another error occurs on the computer screen saying “Unexpected error. Sorry, we ran into a problem. Please try again”.

Windows Defender threat service has stopped restart it now

Well then, how can you get rid of the trouble? Don’t feel vexed since you can easily fix this error after trying the methods below.

Fix You’ll Need a New App to Open This Windowsdefender Link
Fix You’ll Need a New App to Open This Windowsdefender Link

If you get the error “You’ll need a new app to open this Windowsdefender link” in Windows 11/10, how to fix it? Get a solution from this post.

Read More

Fixes for Threat Service Has Stopped Restart It Now

Enable Windows Defender Services in Services

To run Windows Defender or Windows Security, the related services should be running. Or else, you may get the error “Threat service has stopped. Restart it now” in Windows 11/10. The following is how to enable these services in the Services window:

Step 1: Open the services management console by typing services.msc in the search box and clicking Services . Or you can press Win + R , type services.msc and click OK .

Step 2: Locate the following services and make sure the startup type of these services is set to the default values:

  • Windows Defender Advanced Threat Protection Service – Manual
  • Windows Defender Antivirus Network Inspection Service – Manual
  • Windows Defender Antivirus Service – Manual
  • Windows Defender Firewall Service - Automatic

Microsoft Defender Antivirus Service High Memory/ CPU/Disk Usage
Microsoft Defender Antivirus Service High Memory/ CPU/Disk Usage

Do you use Windows Defender in daily life? What if there is an issue with Microsoft Defender antivirus service high memory usage? Let’s explore fixes together!

Read More

If any service is stopped, start it. Just double-click on it and choose Start . To change the startup type, double-click on one service and choose the correct option from the drop-down menu in Startup type .

start Windows Defender Advanced Threat Protection Service

Edit Windows Registry

If the above fix cannot work to remove “threat service has stopped restart it now”, you can try to enable Windows Defender services in Windows Registry.

Before you proceed with the modification of the Windows Registry, it is recommended to back up your registry items since mistaken operations may cause the system to go wrong. To do this work, follow the guide - How to Back up Individual Registry Keys Windows 10/11 .

See how to do this task:

Step 1: Launch Windows Registry Editor by clicking Win + R , typing regedit to the text box, and clicking OK . Or, type regedit to the search box in Windows 10/11 and click the result to open this editor.

Step 2: Click Yes in the User Account Control window to continue.

Step 3: Navigate to this path step by step: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender . Or you can copy & paste the path to the address bar and press Enter .

Step 4: If you see the two items – DisableAntiVirus and DisableAntiSpyware in the right pane, double-click on each one and set the value data to 0 .

If these two items are not displayed, create them: right-click on the empty space and choose New > DWORD (32-bit) Value . Give a name to one. Then, change the value data of each item to 0 .

DisableAntiSpyware in registry

Step 5: Close Registry Editor and restart your Windows PC. Then, go to run Windows Defender to see if the issue is solved.

Besides, there is another thing you can have a shot.

Step 1: Go to the path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinDefend .

Step 2: In the right pane, double-click on the Start item and change its value data to 2 from 4 .

If your PC misses some required services like WinDefend and SecurityHealthService, you cannot see them in this path HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services . To fix “Windows Security threat service has stopped restart it now”, try the next method.

Export the Missing Security Service from Another PC

Make sure the system version of the Windows PC you will export the security services from is the same as yours. Besides, prepare a USB flash drive and connect it to another PC.