When attempting to activate Windows Defender, you may encounter the error: “This app is turned off by group policy.” The two primary causes of this error are as follows: firstly, if your PC belongs to a domain and the domain controller has implemented policies, Windows Defender may be blocked. Secondly, if you’ve installed a third-party antivirus, it might impede Defender, a block that could persist even after uninstalling the third-party application. Consequently, you’ll receive the aforementioned error when trying to enable Defender.
This error can be resolved by requesting your system administrator to activate Windows Defender through Group Policy. Additionally, you can rectify this either by enabling it via the Local Group Policy Editor or applying a registry tweak.
Method 1: Enable Windows Defender via the Local Group Policy Editor
Please note, the Local Group Policy Editor is only available in Windows Enterprise and Pro Editions. To correct this issue, follow these steps:
Method 2: Uninstall Existing Anti-Malware Software
If your PC has another antivirus installed, or one was recently uninstalled, use the appropriate tool to remove all third-party antivirus and antispyware applications. To resolve this issue, follow these steps:
Method 3: Restart Security Center Service
Restarting the Security Center Service can solve the problem. To fix this issue follow the steps below:
Method 4: Enabling Windows Defender from the Registry
Only proceed with this method after attempting the previous steps. Be aware that editing your registry can lead to unwanted effects. Windows disables Defender if it detects another anti-malware software. You can enable this in the registry, ensuring no software conflicts and that Windows remains infection-free. Follow the steps below to fix this issue:
Method 5: Delete Conflicting Registry Entries
Some malware may insert malicious keys into the registry to prevent active antiviruses from running. Follow these steps to locate and remove them from the registry:
