Overview
- Microsoft acknowledged late August that a Defender update bug can show repeated “Microsoft Defender Antivirus is turned off” messages even though protection remains active.
- The problem affects a wide set of releases, including multiple Windows 10 builds (22H2, 21H2, LTSC 2019 and 2016), Windows 11 versions (26H1, 25H2, 24H2, 23H2) and many Windows Server releases.
- Microsoft says the incorrect notifications can appear at startup and intermittently afterward and that they may persist even when notification settings are turned off.
- Users are advised to ignore the misleading pop-ups, confirm actual protection by opening the Windows Security app and checking Virus & threat protection, and wait for the forthcoming Defender update to fix the bug.
- The bug was reported by Insider Release Preview participants and forum users weeks before Microsoft’s public notice, and it follows several prior post-update notification glitches that have raised user concern about update reliability.