Why Windows 10 Support Ends in 2025 and What the New 26H1 Update Means for Windows 11

Microsoft announced that Windows 10 support will end on October 14 2025, and the final cumulative update KB5066791 has been released. After installing the update, some users see a message stating “Your Windows version has reached end of support,” even on systems still covered by ESU.

Microsoft clarified that this is a bug and provided a special Group Policy to roll back the known issue. Administrators must install and correctly configure the supplied policy, disabling the “KB5066791 251020_20401 Known Issue Rollback” value, then restart the system.

Download link: https://download.microsoft.com/download/6adc4d6d-a28c-4194-bb22-f0935faf78c9/Windows%2010%2020H2%2c%2021H1%2c%2021H2%20and%2022H2%20KB5066791%20251020_20401%20Known%20Issue%20Rollback.msi

Inside the patch, a code line reads:

SUPPORTED_Windows_11_0_26H1_Only Windows 11, version 26H1

Translated, it indicates that version 26H1 is officially supported, confirming that this build is not a rumor but an actual Microsoft‑registered version.

Microsoft’s recent Windows 11 release strategy has shifted from two major updates per year to a single annual update, with releases 22H2, 23H2, 24H2, and 25H2. The upcoming 26H1 was first rolled out on the initial batch of Copilot+ PCs and will be fully deployed three months later.

Unlike previous updates, 26H1 is targeted exclusively at new Windows on ARM devices powered by the Snapdragon X2 processor, serving as a “launch pad” to test AI features and low‑level optimizations before they are merged into the next major release, 26H2, for all users.

In summary, 26H1 acts as a market‑segment test rather than a universal update, and the true widely‑available Windows 11 feature set is expected with the annual 26H2 release.