Windows – Microsoft Defender Antivirus is disabled, but back to normal after reboot. How to disable it permanently?

I have Windows 10 ver 2004. Since Windows Defender changed to Microsoft Defender Antivirus I’m unable to turn it off. In Local Group Policy (gpedit.msc) under Computer Configuration/Administrative Templates/Windows Components/Microsoft Defender Antivirus there is a key "Turn off Microsoft Defender Antivirus". Every time I check "enable" and log out or reboot the key is back to "Not configured". How to keep it disabled permanently, and therefore turn off Microsoft Defender Antivirus essentially?

_{(source: windowscentral.com)}

Solution:

I have successfully removed the windows defender service with no side effects so far, other than windows notifying you that the defender service could not start.

Windows 10 Version 2004 build 19041.450

This eliminated defender from the PC

Use a bootable offline registry editor of choice, I used a windows 7 64bit ERD disc to do it, not publicly available but can be found. It has a registry editor.

Once booted into the registry editor navigate to

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetservicesWinDefend

delete the WinDefend key

I would export the key first, then if you want Defender back you can Merge the saved key back into the registry and reboot.

The key may be returned after certain Windows updates, so you will have to delete it again, thanks IGRACH