Microsoft investigates Windows 11 update bugs

Windows 11 KB5120998 software bug mouse cursor glitch Microsoft

Microsoft is investigating several bugs affecting Windows 11 following the release of the optional preview update KB5120998 on August 27, 2026. The update, which introduced highly requested features like a movable taskbar and a resizable Start menu, has caused significant user interface issues.

Users have reported that personalized mouse cursor settings are being reset to standard defaults, with high-DPI cursors often being replaced by large, white cursors. Additionally, some users have experienced desktop wallpapers turning solid black. Microsoft has officially acknowledged the mouse cursor issue, noting that attempts to restore previous customizations have been unsuccessful for some.

Another reported bug causes Windows to intermittently display false notifications stating that ‘Microsoft Defender Antivirus is turned off,’ although the software continues to function normally. Microsoft has advised users to report issues via the Feedback Hub and is working on a resolution.

Entities

Microsoft · Microsoft Defender · Microsoft Defender Antivirus · Windows 11

Claims

What the coverage asserts, and how many sources carry each claim.

[● 4 SOURCES] Microsoft is investigating reports that the KB5120998 update causes mouse cursor personalization settings to revert to standard settings. au.pcmag.com · www.zdnet.com · au.lifehacker.com · uk.pcmag.com
[● 3 SOURCES] A bug in the update can cause Windows to incorrectly report that Microsoft Defender Antivirus is turned off. au.pcmag.com · hothardware.com · uk.pcmag.com
[● 3 SOURCES] The KB5120998 update was released on August 27. www.zdnet.com · hothardware.com · au.lifehacker.com
[● 3 SOURCES] Attempts to restore previous cursor customization settings may be unsuccessful. au.pcmag.com · www.zdnet.com · uk.pcmag.com
[● 4 SOURCES] The KB5120998 update includes features to reposition and move the Taskbar. au.pcmag.com · www.zdnet.com · au.lifehacker.com · uk.pcmag.com
[● 2 SOURCES] The KB5120998 update is a preview update and is not mandatory. www.zdnet.com · au.lifehacker.com
[● 2 SOURCES] The update can cause desktop wallpapers to turn black. au.pcmag.com · uk.pcmag.com
[● 3 SOURCES] High-DPI mouse cursors may be replaced with larger, white cursors. au.pcmag.com · www.zdnet.com · uk.pcmag.com