Microsoft Windows Update certificates to expire in 2027

Microsoft has announced a major certificate rotation for Windows Update, which will impact how devices connect to update servers to ensure authenticity and security via HTTPS. Two key certificate sets are scheduled to expire on May 17, 2027, and June 19, 2027.

For most users who regularly install monthly security patches, the transition should be seamless as replacement certificates are included in standard updates. However, devices that have not been updated for an extended period—such as machines kept in storage, older corporate computers, or systems running unsupported versions—risk losing the ability to download security patches and functional updates directly from Windows Update.

Specific deadlines depend on the operating system version:

• Windows 11 (24H2) and Windows Server 2025: Must have the September 2025 security update or newer by June 19, 2027. • Other supported Windows 11 versions, Windows Server 2022, and supported Windows 10 versions: Must have the July 2026 update or newer by June 19, 2027. • Windows 10 Enterprise 2019 LTSC, Windows Server 2019, and 2016: Must have the July 2026 update or newer by May 17, 2027.

Devices receiving updates via Windows Server Update Services (WSUS) are reportedly not affected by this change.