Microsoft says devices running unsupported versions of Windows will stop receiving security updates after next year’s Windows Update certificate rotation.

To ensure devices keep receiving updates, admins and users must upgrade to a supported version of Windows before the Windows Update certificates expire in May and June 2027.

“As a standard security practice, these certificates have an expiration date. This means that they eventually need to be rotated (that is, replaced by new certificates). A set of these certificates will expire on May 17, 2027 and June 19, 2027,” Microsoft said on Thursday.

It also added that devices on unsupported versions of Windows “will lose access to Windows Update services and won’t receive any updates as a result” and recommended “upgrading to a supported version of Windows client or server.”

Microsoft shared the following detailed guidance on the required actions by Windows version:

• Windows 11, version 25H2 and later: No action is required.
• Windows 11, version 24H2 and Windows Server 2025: Install the September 2025 security update or later before June 19, 2027.
• Other supported versions of Windows 11, Windows Server 2022, and Windows 10: Install the July 2026 security update or later before June 19, 2027.
• Windows 10 Enterprise 2019 LTSC, Windows Server 2019, and Windows Server 2016: Install the July 2026 security update or later before May 17, 2027.
• Other Windows versions: Upgrade to a supported version of Windows client or Windows Server.

Microsoft advised IT administrators to identify all devices running older or unsupported Windows versions before the Windows Update certificate rotation in 2027.

They should also deploy monthly Windows updates on all supported devices to keep them up to date and create an upgrade plan for unsupported devices before May and June 2027.

“And if you do need to act on older device populations, there’s still time! Review, update, and plan upgrades for unsupported versions before the May 2027 or June 2027 certificate expiration dates,” it added.

However, this doesn’t apply to devices that receive updates from Windows Server Update Services (WSUS), which downloads updates and distributes them across enterprise networks.

Last month, Microsoft released Windows 11, version 26H2 (also known as the Windows 11 2026 Update), which is now generally available for eligible Windows 11 24H2 and 25H2 systems as a small enablement package (instead of a full OS replacement) in a phased rollout that will expand over the next few months.