Defender Antivirus "turned off"

kirbster 1 120 Reputation points
2026-07-25T13:27:00.0666667+00:00

Windows 11 25H2 26200.8968 Release Preview

I keep getting notifications that Defender Antivirus is turned OFF. Every last toggle in Defender settings is toggled on, I get Antivirus updates, am able to run scans but I keep getting the notification window that Antivirus if off. I have notifications "toggled off" but still get the antivirus off notifications.

This is happening on a 2 day old Clean Install of Windows 11.

Any ideas why this is happening?antivirusoff

Windows Insider program | Windows Insider preview | Security, privacy, and accounts
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  1. Will F 5 Reputation points
    2026-08-16T17:51:35.37+00:00

    Seeing exact same symptoms for Defender Antivirus showing as off, but all the toggles showing as running (and I can use the right click context menu in Explorer to initiate an on-demand scan, so I know it's not all broken). I have no other antivirus installed, and I am not enrolled in insider; currently running the August 2026 normal update (build 26200.9168). Microsoft Defender Antivirus service was not showing up in Services.msc, either.

    I ran Get-MpComputerStatus as suggested above and all three responded as if they were running. After running Get-MpComputer Status for the AV services, sfc /scannow, and the DISM check (no issues identified for either of the latter), the Defender AV Network service, Defender AV service, and Defender Core service all show up in Services.msc. I still have "Microsoft Defender Antivirus is turned off", but at least the services show up as running.

    Whatever is causing this issue is not just for release preview builds, but I appreciate the alternative method to confirm that things are running via PowerShell.

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  2. Evan 10 Reputation points
    2026-08-14T09:38:03.88+00:00

    I'm seeing this on a normal build.

    Apart from that warning it all looks fine, PS reports it's all enabled.

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  3. CrazyKats 19,245 Reputation points Volunteer Moderator
    2026-07-29T16:27:44.7466667+00:00

    Just wondering if either of the posters have a second AV

    that could be turning it Off.

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  4. jens 0 Reputation points
    2026-07-29T16:24:36.6866667+00:00

    Can confirm here as well, been like this for the past few insider builds, not entirely sure if it's Insiders related.. but i'm guessing it is.

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  5. Alex-L 12,555 Reputation points Microsoft External Staff Moderator
    2026-07-26T08:11:05.8333333+00:00

    Hi kirbster 1

    Since you're on a Windows 11 Release Preview build (25H2 26200.8968) and Defender is clearly updating, scanning, and all protection toggles are enabled, this may be a Windows Security reporting bug rather than Defender actually being disabled.

    A few things to check:

    1. Open PowerShell (Admin) and run: 
         Get-MpComputerStatus | Select AntivirusEnabled, RealTimeProtectionEnabled, AMServiceEnabled
      If these return True, Defender is running despite the warning. Open services.msc and confirm Microsoft Defender Antivirus Service (WinDefend) is running. Reset the Windows Security app: Settings > Apps > Installed apps > Windows Security > Advanced options > Reset.
    2. Run: 
         sfc /scannow
   DISM /Online /Cleanup-Image /RestoreHealth
      Check if any third-party security software (including remnants from a previous install) is registered with Windows Security Center.

    Because this is occurring on a Release Preview Insider build, if Get-MpComputerStatus shows Defender is enabled, I'd lean toward a false notification/reporting issue rather than a protection issue.

    As this is a public forum, no one here can access internal builds to investigate this for you. You can submit feedback through Feedback Hub (Win + F) and include a screenshot plus a copy of the PowerShell output above.

    Hope this will get sorted out soon!

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