Windows Defender is the default security program for Windows PCs. It is not the best to protect your PC against malware, spyware and other security threats. But it is a good choice. So, Many users are using it as their only security solution. Because, It is free and lite. It doesn’t slow down your PC like other third-party softwares. Despite of this advantage, You may face a trouble. Sometimes, You may notice that windows defender is not protecting your PC. But you did not turn it off by yourself. When you try to enable it, You may experience it is not working, turned off or unable to start. This is a big concern indeed. You may see a message “Windows Defender has been turned off and it isn’t monitoring your computer“. But, You can fix this issue by yourself.
How to Fix Windows Defender not Working / Turned Off:
It very easy to resolve this issue. But make sure, You have not installed other third-party antivirus. Because, These programs automatically turn your built in security system off. In that case, You should uninstall that third-party program. You also should check your time and zone. Because, Incorrect time zone, time and date may creates problem. So, Correct it. Even after doing it, You may still face the windows defender unable to start problem. In that case, You will need to follow the steps given below to fix this problem.
Steps to Fix Windows Defender has been Turned Off and isn’t Monitoring Problem:
Here are they –
- Open Action Center of Windows and check if you can enable Windows Defender. If it fails, Follow next instructions.
- Press CTRL + R from keyboard to launch RUN.
- Type services.msc.
- Find Windows Defender service and double click on it. Now, If you see it is stopped, Click on Start and set startup type to Automatic. Do the same thing for Windows Defender Network Inspection Service.
- Now, Press Windows Logo Key + X from keyboard. Then select Command Prompt (Admin). Run the following commands.
regsvr32 wuaueng.dll regsvr32 wucltui.dll regsvr32 softpub.dll regsvr32 wintrust.dll regsvr32 initpki.dll regsvr32 wups.dll regsvr32 wuweb.dll regsvr32 atl.dll regsvr32 mssip32.dll
- Sometimes, Windows may ask you to check your malware settings or enable it. When you click on Turn on now, You may see an error message like – “There are no new definitions available to download for Windows Defender“. But following command may fix this issue. Just run command prompt as admin like before and run the command.
- If you get message like “WMI repository is not consistent“, Run the following command.
- Now, Restart your PC after completing the process.
- Try to enable windows defender now.
- The following commands may not work first time, So, You should try at least 2/3 times.
- If these commands don’t work, Try next commands. At first type net stop winmgmt and press Enter.
- Now, Press Y to continue. Then, Type the following commands and press Enter one by one.
cd %windir%\system32\wbem ren repository repository.old net start winmgmt
I hope, It will fix the issue.
Additional Steps to Fix Unable to Start Windows Defender:
If the above methods failed to fix the issue, You may try the following methods. I hope, These will help you.
1. Restarting Security Center:
Sometimes, Restarting Security Center may help you. To do it –
- Just open services by typing services.msc and hitting Enter in RUN.
- Find Security Center and right click on it.
- Click on Restart.
Now, Try to run windows defender and enable it.
2. Deleting Conflicting Registry Entry (Caution):
You can try to delete some registries. But, It may occur other problems (Rarely). So, You have to do it with your own risk. To do it –
- Press Windows Logo Key + R. Type regedit and press Enter.
- Navigate to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options.
- Now, Find MSASCui.exe, MpCmdRun.exe or MsMpEng.exe and right click on them. Then click on Delete.
- Now, Try to Enable windows defender.
3. Running Clean Boot:
You can run a clean boot. It confirms, If there is any third-party software or service that is preventing windows defender to be turned on. Know: How to Run Clean Boot.
4. Fixing Corrupted System Files:
Damaged or corrupted system files may create this problem. So, I recommend you to run sfc command. Know more details from here: Fix Corrupted Windows System Files.
I hope, These steps will be helpful for you to fix windows defender unable to start problem.