Windows 11 Update KB5120998 Causes Mouse Cursor and Wallpaper Issues

Microsoft has officially confirmed widespread issues stemming from its latest Windows 11 update, KB5120998, released on August 27, 2026. The problematic update is reportedly causing severe disruption to the user experience, most notably with mouse cursor functionality and display wallpapers.

Users have reported a range of bizarre behaviors with their mouse cursors after installing the optional update. These include the cursor disappearing entirely, becoming excessively large or small, or reverting to default settings and changing color and size unexpectedly. Some users even found their custom cursor changes being completely ignored by the operating system. The widespread nature of these complaints has prompted Microsoft to issue a statement acknowledging the problem directly in the update's release notes.

"Microsoft has received reports indicating that mouse cursor personalization settings are being changed or reverted to certain standard settings," the company stated. "This occurs following installation of Windows updates released August 27, 2026 (KB5120998) and later." This admission confirms that the update, which also targeted improvements to the Taskbar, Start Menu, and Windows Search, has introduced significant bugs.

Wallpaper Glitches Add to User Frustration

The problems extend beyond just the cursor. Reports indicate that the same update is causing users' wallpapers to turn completely black. Even after attempting to reapply custom wallpapers, the system continues to display a black screen, significantly impacting the visual experience of the operating system. This dual-pronged attack on personalization settings appears to be a direct consequence of the buggy KB5120998 update.

Fortunately for affected users, the solutions appear straightforward, albeit inconvenient. Both the mouse cursor anomalies and the black wallpaper issues are reportedly resolved by uninstalling the KB5120998 update. This rollback effectively reverts the system to its previous state, resolving the bugs introduced by the faulty patch. Microsoft is expected to release a subsequent patch to address these specific problems permanently in the coming days.

This incident highlights the ongoing challenges Microsoft faces in ensuring the stability of its operating system updates. While optional updates are typically meant to offer early access to new features and improvements, they can sometimes introduce unforeseen bugs that affect a significant number of users. The company's swift acknowledgment, however, suggests a commitment to addressing user feedback promptly. For now, users experiencing these frustrating Windows 11 glitches are advised to uninstall the update to restore normal functionality.

The update, codenamed KB5120998, rolled out as an optional cumulative update for Windows 11. While it promised enhancements to core components like the Start menu and search functionality, its deployment has been marred by these critical bugs. This situation underscores the importance of rigorous testing before the release of any significant software update, particularly those that affect core system aesthetics and user interaction elements. The fix for these issues is anticipated, but users are left managing the current disruptions by manually removing the problematic installation.