Microsoft has confirmed a bug in Microsoft Defender that causes Windows to display misleading notifications prompting users to "Turn on virus protection" even though the antivirus is already active with real-time protection enabled.
The false alerts began appearing after the latest Microsoft Defender updates. They trigger either when the computer starts or during regular operation. Pressing the notification does nothing to resolve the issue and simply redirects users to the main page of the Windows Security application. While the banner can be dismissed manually, it often reappears with the same message shortly afterward.
The problem impacts Windows 11 versions 23H2, 24H2, and 25H2, as well as Windows 10 and all Windows Server releases that use the current version of Microsoft Defender. The root cause lies in the antivirus update itself rather than any specific operating system build.
The notification system behaves particularly aggressively, bypassing standard Windows notification settings and continuing to appear even when "Do Not Disturb" mode is enabled. Microsoft is actively working on a fix and plans to include it in an upcoming Microsoft Defender update, although no release date has been announced.
Security experts still recommend verifying the actual status of protection before ignoring any such banner, as similar messages can be generated by genuine malware. Users can check the status in Windows Security → Virus & threat protection, ensuring that Real-time protection is turned on. For a more detailed verification, the following PowerShell command can be executed:
Get-MpComputerStatus | Select-Object AntivirusEnabled,RealTimeProtectionEnabled,AMServiceEnabled
If all three parameters return True, Microsoft Defender is functioning correctly and the notification can be safely disregarded.
