Microsoft is updating the certificates that authenticate communication between Windows PCs and Windows Update servers, with the current certificates expiring on May 17 and June 19, 2027. Users will generally not need to take action as the new certificates will be included in regular monthly security updates. Specific requirements for different Windows versions include:
- Windows 11 25H2 and later: No action required.
- Windows 11 24H2: Must install the September 2025 security update or newer.
- Other supported Windows 11 and Windows 10 versions: Need the July 2026 update or later before June 19, 2027.
- Windows 10 Enterprise 2019 LTSC, Windows Server 2019, and Windows Server 2016: Deadline of May 17, 2027.
Devices running unsupported versions will lose access to Windows Update services. Home users with Windows 10 PCs not enrolled in Extended Security Updates (ESU) after October 2025 may miss the critical July 2026 patch. Microsoft has extended ESU coverage until October 12, 2027. Users should check their update history to ensure they have received a cumulative update from July 2026 or later.