Overview
- Microsoft released the optional preview update KB5120998 that upgrades Windows 11 25H2 and 24H2 to builds 26200.9278 and 26100.9278 and restores a movable taskbar, a resizable Start menu, and a smaller taskbar option.
- The preview also adds controls to stop web and Microsoft Store results from appearing in Windows Search and includes enterprise changes such as just‑in‑time administrator protection, Microsoft Execution Containers, and removal of the WMIC utility.
- Within hours of the rollout users reported two recurring cosmetic regressions: custom mouse pointers reverting to an oversized white legacy cursor and desktop wallpapers resetting to a flat black background.
- Microsoft engineer Jen Gentleman has urged affected users to submit Feedback Hub reports while Microsoft investigates, and users say uninstalling the optional update restores cursor and wallpaper settings as the only confirmed workaround so far.
- The update is staged and optional with large .msu offline installers that bundle AI models, Microsoft has not published a formal known‑issue notice or issued a Known Issue Rollback yet, and administrators are advised to skip the preview until fixes arrive.