Microsoft's Windows 11 Optional Update KB5120998 Causes Mouse Cursor Glitches
Microsoft's optional Windows 11 update KB5120998, released on August 27, has triggered widespread mouse cursor anomalies, including disappearing or resized cursors. Users report that uninstalling the update resolves the issue, while Microsoft has acknowledged the reports and launched an investigation. The update also resets desktop wallpapers and causes font display problems.
Microsoft released the optional Windows 11 update KB5120998 on August 27, upgrading the system to Build 26200.9278 (25H2) and Build 26100.9278 (24H2). The update introduced a resizable Start menu, a movable taskbar, and a Windows Search feature that removes Bing and preinstalled software. Shortly after the rollout, numerous users reported mouse cursor anomalies, and Microsoft has confirmed the issue and launched an investigation.
Affected users have experienced varying symptoms, including the cursor disappearing entirely, its size increasing or decreasing, and its color being reset to the default. Some users found that a white cursor turned into a large black cursor, and vice versa. Those using custom cursor schemes or animated cursors discovered that their settings were reverted to the standard default, and even attempts to restore the cursor in settings were not saved, with the cursor automatically returning to the abnormal state.
Some users tried conventional fixes such as resetting the registry, running DISM commands, and restoring default mouse cursor settings, but a huge cursor still appeared on the desktop. The problem disappeared after uninstalling KB5120998, and other users reporting cursor anomalies confirmed that uninstalling the update was the only effective solution. Microsoft stated in a statement that it had received the reports and was investigating whether the issue was indeed caused by Windows Update. Since the problem appeared immediately after the update installation and disappeared immediately after uninstallation, the evidence points to the optional update.
In addition to cursor issues, KB5120998 has also been found to reset desktop wallpapers and cause font display abnormalities. Microsoft has not yet responded to these two issues.