Microsoft Investigates Windows 11 Update Bugs and Antivirus Glitches

Microsoft is investigating several bugs following the August 27 release of optional preview update KB5120998 for Windows 11 versions 24H2 and 25H2. The update has caused desktop wallpapers to turn solid black and triggered mouse cursor glitches, where customized pointers are replaced by default white cursors or change size unexpectedly. Some users also report blurry or pixelated text.

Microsoft acknowledged that cursor personalization settings are being reverted to standard settings, resulting in appearance regressions. Separately, the company reported a bug in the August update for Microsoft Defender Antivirus. This glitch triggers false notifications stating the antivirus is turned off, although the software continues to function normally.

Software engineer Jen Gentleman reminded users that the update is optional and requested detailed reports via the Feedback Hub. While the company works on official fixes, users can resolve the cursor and wallpaper issues by uninstalling KB5120998 through the Windows Update history settings.