“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
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.
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
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”.
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.
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
in the search box and clicking
. Or you can press
Win + R
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
If any service is stopped, start it. Just double-click on it and choose
. To change the startup type, double-click on one service and choose the correct option from the drop-down menu in
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.
Step 1: Launch Windows Registry Editor by clicking
Win + R
to the text box, and clicking
. Or, type
to the search box in Windows 10/11 and click the result to open this editor.
Step 2: Click
in the User Account Control window to continue.
Step 3: Navigate to this path step by step:
. Or you can copy & paste the path to the address bar and press
Step 4: If you see the two items –
in the right pane, double-click on each one and set the value data to
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
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:
Step 2: In the right pane, double-click on the
item and change its value data to
If your PC misses some required services like WinDefend and SecurityHealthService, you cannot see them in this path
. 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.
Step 1: Go to
, right-click on
to export the file to your USB drive. Then, name the file as
Step 2: Eject the USB drive from the PC and plug it into your computer.
Step 3: Copy the exported registry file to your desktop from the USB drive and double-click on it to merge it to Windows Registry.
Step 4: Restart the PC and see if the issue – Windows Security threat service has stopped restart it now is fixed.
Uninstall Third-Party Antivirus
Sometimes “Threat service has stopped. Restart it now” is only an informational message. If you install any third-party antivirus program on your Windows 10/11 PC, Windows Defender will stop working automatically and shows you the message. Go to uninstall this software since it can interfere with Windows Security/Windows Defender.
Just go to Control Panel and click
Uninstall a program
category. Right-click on the antivirus program and click
Sometimes “threat service has stopped restart it now unexpected error” is caused by missing or corrupted system files. So, you can try to run an SFC and DISM scan to check for the entire operating system and repair corruption to fix some issues like the Windows Security issue.
Step 1: Type
in the search box in Windows 10/11 and click
Run as administrator
from the right pane.
Step 2: Type
to begin verification.
Step 3: After finishing the SFC scan, type
Dism.exe /Online /Cleanup-Image /Restorehealth
to the CMD window and press
. This process will take a few minutes and wait patiently.
Repair Windows 10/11 via an In-Place Upgrade
Another solution to fix the Windows Defender issue is to perform an in-place upgrade and you can also have a shot. Before you upgrade this PC, it is recommended to back up your important data and create a system image to avoid something wrong.
To do this task, we strongly recommend using MiniTool ShadowMaker, a professional
PC backup software
for Windows 11/10/8/7. It can be used to back up files, folders, systems, disks, and partitions. This program can meet your requirements well. It is free to use to enjoy all the features in 30 days. Just click the following button to download it.
Step 1: After downloading MiniTool ShadowMaker Trial Edition, double-click on the icon to launch it on your PC.
Step 2: Move to the
tab, you can find this software backs up the system by default since all the system-related partitions are selected as the backup source. If you want to back up data, go to
Source > Folders and Files
, check the items you want to back up, and click
Step 3: Go to
and choose a path to save the backup. An external hard drive or a USB flash drive is recommended.
Step 4: Click the
Back up Now
button to execute this task at once.
Next, it is time to perform an in-place upgrade to fix “threat service has stopped restart it now”. See the guide below to know how to do this work.
To repair your Windows 10/11 via the upgrade, you need to ask Media Creation Tool for help and here we take Windows 10 as an example.
Step 1: Go to the
Download Windows 10
page from Microsoft and download Windows 10 Media Creation Tool by clicking the
Download tool now
Step 2: Double-click on the exe file on your PC and click
in the User Account Control interface.
Step 3: After a few things are ready, click the
button to agree to applicable notices and license terms.
Step 4: Check the option of
Upgrade this PC now
to go on.
If you need to create a bootable USB drive or download an ISO file of Windows 10, tick the option of
Create installation media (USB flash drive, DVD, or ISO files) for another PC
“Threat service has stopped restart it now” is a common issue on Windows 10/11. If your PC confronts this annoying problem, try the solutions above one by one and you should easily get rid of the trouble. If you find some other methods to help you out, you can write it in the comment below.
Besides, after fixing the issue, we strongly recommend backing up your PC to keep the machine safe. In addition, try some other reliable ways to protect your PC against viruses and malicious programs since Windows Defender is not enough to keep the PC safe.
Vera is an editor of the MiniTool Team since 2016 who has more than 5 years’ writing experiences in the field of technical articles. Her articles mainly focus on disk & partition management, PC data recovery, video conversion, as well as PC backup & restore, helping users to solve some errors and issues when using their computers. In her spare times, she likes shopping, playing games and reading some articles.