If you had to change it to Not Configured, reboot now. On the right, double-click Turn off Windows Defender Antivirus. Navigate to Computer Configuration > Administrative Templates > Windows Components > Windows Defender Antivirus. Press the Windows Key + R and type in gpedit.msc.
Since the error message states that Windows Defender is turned off by Group Policy, let's look there next.
If you can't access Windows Defender from the System try, go to your Control Panel > Updates & Security > Windows Security > Virus & threat protection > Virus & threat protection settings.Ģ: Enable Windows Defender using Group Policy You can verify this by going to Windows Defender Security Center from the System tray > Virus & threat protection > Virus & threat protection settings > Real-time protection and making sure that's toggled on. The most obvious solution is to check that Windows Defender hasn't been turned off. TIP: Hard to fix Windows Problems? Repair/Restore Missing Windows OS Files Damaged by Malware with a few clicks