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.

If you turn off the Notifications toggle in Windows 11, you must open the Microsoft Defender security application to check if your system is infected with malware.

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 ...