Microsoft says the certificates Windows uses to trust Windows Update expire on May 17, 2027 and June 19, 2027. A PC without the replacement certificates loses access to Windows Update after its deadline. Most PCs that install monthly updates need to do nothing.

What Microsoft says to do

Microsoft's Windows message center notice, posted October 8, lists these steps:

  • Windows 11 version 25H2 or later: no action needed.
  • Windows 11 version 24H2: install the September 2025 security update or later before June 19, 2027.
  • Other supported Windows 11 versions and Windows 10 with Extended Security Updates (ESU): install the July 2026 security update or later before June 19, 2027.
  • Windows 10 Enterprise 2019 LTSC: install the July 2026 security update or later before May 17, 2027.
  • Other Windows versions: upgrade to a supported version.

Microsoft also lists Windows Server versions, which this article does not cover.

Who is at risk

Microsoft says a device without the replacement certificates will lose access to Windows Update after the deadline. It says "most devices" on a supported Windows version need no action if they are current with monthly updates. The change does not apply to devices that get updates from Windows Server Update Services (WSUS).

BleepingComputer reports that devices on unsupported Windows versions will therefore stop receiving security updates. Microsoft's notice says to upgrade those to a supported version. Windows 10 counts as supported only with ESU. Microsoft's message center also says Windows 11 version 24H2 Home and Pro reaches end of updates on October 13, 2026, so move those PCs to a newer version. Check winver to see which version you run.

What to do now

Run Windows Update and install the latest monthly update, which covers the July 2026 requirement. Old spare laptops and PCs that rarely connect are worth checking now rather than next spring. If a PC cannot run a supported Windows version, plan to replace it before the dates above.

What we could not confirm

We read Microsoft's notice in the message center. We did not test a PC or check how many devices this affects. We did not read the full certificate rotation guide Microsoft links.