Windows UpdatesWindows 11, version 25H2
What's new in KB5120998 (Windows 11 build 26100.9278)
KB5120998 is an optional preview update released on August 27, 2026, for Windows 11 version 24H2 and version 25H2. It updates your system to OS Build 26100.9278 or OS Build 26200.9278, bringing non-security fixes, quality refinements, and system reliability improvements ahead of the next scheduled monthly update. You can install it manually through Windows Update under optional updates.
Priya Natarajan