Check Registry value Use System File Checker Use Terminal to turn Protection on or off Reset Windows Defender to default settings. To learn more about these solutions, continue reading.

In any case, when you install a 3rd-party security software, Windows Defender will turn itself off. Read: How to Turn On or Off Security Questions using Registry or Group Policy ...

Turn off ‘Real-time protection’ to temporarily disable Microsoft Defender. For permanent removal, you will need to install another antivirus program, as Windows automatically activates ...