Overview
- Microsoft released the optional Windows 11 preview KB5120998 on August 27, 2026, which added a movable taskbar, a resizable Start menu, and the option to remove Bing from search.
- Soon after the rollout users reported that mouse cursor customizations reverted or failed to load and that desktop backgrounds and other personalization settings could display as a solid black color.
- Microsoft has confirmed two separate regressions: the mouse personalization reset was linked to code used in non‑English Windows installs and desktop settings can fail to load, preventing manual restoration.
- The company also acknowledged that Microsoft Teams and the new Outlook may crash on some ARM devices after recent updates and said it will include a fix in an upcoming update cycle.
- Because KB5120998 is an optional preview delivered via a phased Controlled Feature Rollout, Microsoft advises uninstalling the preview or avoiding it until a patch lands and warns that more machines could show problems as the rollout continues.