False Alarm! Why Windows 11 Keeps Saying Your Antivirus Is Off
Windows 11’s built-in security program, Microsoft Defender Antivirus, is a solid pick for keeping you safe. Best of all, it’s readily installed and running the moment you boot up the OS for the first time. Which is why, if you’ve been getting spammed by notifications claiming that “Microsoft Defender Antivirus is turned off” when everything seems okay, it’s only natural to be a little bit worried.
Fortunately, Microsoft has broken the silence about this weird issue, stating that the repeated notifications are a bug and will be rectified soon. So, if you’re seeing the notification pop up and you’ve double-checked that it’s still on, you have nothing to worry about.
Windows 11 is showing a “Microsoft Defender Antivirus is turned off” notification even when it’s on
It’s a little scary, but everything is fine under the hood
As spotted by Windows Latest, Microsoft has updated its documentation on known issues for Windows 11, version 25H2. A new issue has appeared titled ‘Incorrect notifications that “Microsoft Defender Antivirus is turned off,”‘ both logged and posted on August 28th, with the following description:
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 you turn off notifications.
If you get this alert on your PC, first double-check that Microsoft Defender Antivirus isn’t actually turned off. If you see that everything is turned on and working fine, you need not worry; the messages are a false alarm, and your computer is fine.

As if there’s not enough junk we get messaged!!
Thanks for letting us know about this! I submitted a report about this through my PC because I keep getting this message and I’ve never gotten a response from Microsoft. So it’s nice to know someone’s looking out for us and letting us know what’s going on.