Windows Defender falsely reports it's turned off; Microsoft confirms bug and promises fix

The issue was first flagged by Windows Latest, and Microsoft subsequently acknowledged it on its Windows release health dashboard. In a statement, Microsoft said that 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 working correctly and all settings show it as active.

Microsoft said the warnings may appear when Windows 11 first boots and intermittently afterward, and they can show up even if notification settings are disabled. The problem also affects Windows 10, according to the company.

The software giant said it is working on a fix that will be delivered in an update for Defender Antivirus, but no release date has been provided. TechRadar notes that the bugged pop-up asks users to click to re-enable protection, but since protection was never disabled, clicking is unnecessary and the alert eventually returns.

User complaints on Reddit indicate the bug has been present for at least a week, and Windows Latest reports it may date back to early August, though Microsoft only acknowledged it on its health dashboard a few days ago. One Redditor described the issue as "harmless but annoying."

While the false alerts are not a security risk, TechRadar advises users who see the warning to double-check the actual status of Defender. This can be done by opening Windows Security, searchable from the taskbar, and looking under "Virus & threat protection," which will display the correct status and flag any genuine problems.