Microsoft has asked its customers to disregard a misleading alert that Defender Antivirus is turned off on their systems. The issue affects all supported versions of Windows, including the latest releases of Windows 11 and Server 2025. This isn’t an isolated problem – it’s the fourth time this year Microsoft has told users to ignore incorrect alerts and errors triggered by updates.
The trouble started when users installed the latest Defender updates in the Release Preview Channel of the Windows Insider program back in June. Since then, a growing number of people have been receiving notifications in the Windows Security app that Defender Antivirus is turned off, even though it’s still active and functioning properly. These warnings pop up on startup and can reappear periodically, despite users turning off notification settings.
Microsoft has confirmed that this issue affects all supported versions of Windows, including the latest releases of Windows 11 26H1 and Windows Server 2025. The company is quick to reassure customers that Defender Antivirus is still working as intended, but it’s unclear why these alerts are being triggered in the first place. In a statement on its release health dashboard, Microsoft explained: “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.”
This isn’t the first time this year Microsoft has asked users to ignore incorrect alerts. In April, the company fixed a bug that caused invalid error messages after installing Windows Recovery Environment updates. Similarly, in July, users were advised to disregard Windows Firewall warnings triggered by the June preview update. It’s becoming increasingly clear that Microsoft is having trouble shaking off these kinds of issues with its software.
Microsoft has promised to release a fix for this issue in a future Defender Antivirus update. Until then, customers are being told to simply ignore the misleading alerts and carry on using their systems as normal. This might be frustrating for some users, but it’s not uncommon in the world of cybersecurity – even the biggest players can have teething problems with new software releases.
So what does this mean for you? If you’re a Windows user who has recently installed Defender updates, don’t panic if you see these alerts popping up. They’re just a glitch and won’t compromise your security. In the meantime, Microsoft will work on fixing the issue and releasing an update to resolve it.
Source: Bleeping Computer — 2026-08-31