Microsoft on Friday reported that a glitch is causing Windows to tell users that Microsoft Defender Antivirus is turned off when it is in fact fully functional, a bug that the vendor says it is working to fix.
Consultants say that this advisory raises a major concern in that it will train users to ignore critical alerts, which makes them far more susceptible to attacks.
The Microsoft release health dashboard update on the issue reported: “After installing the latest updates for Microsoft Defender Antivirus, notifications might appear stating that ‘Microsoft Defender Antivirus is turned off’ even though the antivirus is functioning correctly and all settings show it as active. These notifications can appear when Windows starts and intermittently afterward. They persist even if notification settings are turned off. This issue can be observed in any version of Windows or Windows Server with Microsoft Defender Antivirus running with the latest Defender updates.”
The post added: “We are working to release a resolution in a future Microsoft Defender Antivirus update and will provide more information when it is available.”
It then listed the various Windows client and server versions impacted: everything from the current Windows 11, version 26H1 and Windows Server 2025 back to Windows 10 Enterprise LTSC 2016 and Windows Server 2012.
