Therefore, to make sure that it is turned on, head over to the Settings app from the Windows Start Menu.

Most of the times, due to any unknown reasons, the Windows Defender gets disabled. The first step here is to see whether Windows Defender is currently turned on or not. Thus, to solve this problem, the following methods should be followed. This error mostly pop-ups when the currently installed anti-virus on the system disables the Windows Defender, to avoid any software conflicts and complications. But, sometimes it can throw up errors saying that Windows Defender is blocked by Group Policy. Windows Defender is fantastic software, that will not only protect your operating system from malware attacks but also will eat up fewer resources on your PC than a traditional anti-virus.