Hello,
Thank you for posting your query on Microsoft Community.
As per description, you are unable to turn off windows defender.
I suggest you try restarting Windows Defender service and check if issue is resolved. To do so kindly follow the below given steps:
- Press Windows key + X key and type **services.msc,**hit enter.
- Search Windows Defender Service.:1) Windows Defender Service; 2) Windows Defender Network.
- Right click on each and press Start.
- Restart your computer and check if issue persist.
Hope this information is helpful. Please do let us know if you need further assistance with Windows, we’ll be glad to assist you.