On October 8, Microsoft posted a notice to administrators, Message Center item MC1491763, saying the certificates that let a PC establish a trusted connection to Windows Update expire on May 17, 2027 and June 19, 2027. A PC that does not hold the replacement certificates by then stops receiving updates. For a home PC that installs its monthly updates, the notice says the replacements are inside Windows security updates already released, so for most people there is nothing to do except keep updating.
We read the notice as mirrored on the Message Center archive MC1491763, not on a Microsoft page, so the wording below is that copy's. The dates are not in dispute across the coverage we found; the minimum update for Windows 11 24H2 is, as explained further down.
Which update each version needs
The notice gives a table. This is its content, in plain words:
- Windows 11 25H2 and later: no action.
- Windows 11 24H2 and Windows Server 2025: the September 2025 security update or any later one, before June 19, 2027.
- Other in-support Windows 11 versions, Windows Server 2022 and in-support Windows 10: the July 2026 security update or any later one, before June 19, 2027.
- Windows 10 Enterprise 2019 LTSC, Windows Server 2019 and Windows Server 2016: the July 2026 security update or later, before the earlier date, May 17, 2027.
- Any other Windows version: the notice says to move to a supported version before the dates.
Not every report matches the table. One article published the day after the notice described the 24H2 requirement as typically the July 2026 update, and was vague about it. Where the two differ, the Message Center table is the primary source and the press summary is not, so we follow the table. Either way, a PC that installed any monthly update this summer already holds both.
Who this does not touch
The notice says the change does not apply to devices that get their updates from WSUS, the server software companies use to hand updates to their own PCs. If your PC belongs to an employer or a school, its IT department decides when updates arrive, and the notice is written for them.
It also says that supported devices that fall behind past the expiry dates can still get the needed update from the Microsoft Update Catalog or through their management tools. That is a recovery path for a PC that missed the window, not a plan.
What happens to a PC that misses it
According to the notice, devices on unsupported Windows versions lose access to Windows Update and stop receiving updates. That sentence is about the unsupported group. The notice does not say what a supported PC without the certificates sees on screen, whether an error code, a stalled download or nothing at all, so we cannot tell you what the symptom looks like. If a PC stops finding updates after the dates, our walkthrough on what to do when Windows Update stalls or fails covers the general causes, but the notice does not link this problem to any of them.
How to check your PC
The notice does not describe a way to check. The route below is our reading, not Microsoft's instructions: open Settings > Windows Update > Update history and look for a cumulative update dated July 2026 or later. For 24H2, an entry from September 2025 or later is enough under the table. The version itself shows under Settings > System > About, as we described in the piece on 24H2 reaching the end of updates this month.
A caution about that PC: 24H2 Home and Pro stop getting monthly updates after October 13, 2026. A 24H2 PC that installs the October update on that day holds the replacement certificates under both versions of the requirement. One that stops updating before then and has nothing from the last year is the case the notice is aimed at.
What changes for you
If your PC updates on its own and runs 25H2 or 26H2, nothing. If it runs 24H2, move to a newer version before the end of updates anyway; the certificate deadline is a second reason, not the first. If it runs Windows 10, the order of the dates matters less than the support status: what Microsoft extended for Windows 10 explains who is covered, and the notice's own wording only speaks of in-support Windows 10.
The date that is hardest to see coming is the one for a PC nobody opens. A spare laptop in a drawer, a family PC with updates paused for years. Those are the ones that reach June 2027 without the replacement, and turning on and updating them well before then is the cheap fix.
If a PC does not update at all right now, start with the step-by-step guide to Windows Update stuck or failing. If you are deciding between versions, what Windows 11 26H2 changes on your PC covers the small download that extends support.
Last updated October 10, 2026