Windows 11 KB5120998 update resets desktop settings, wallpaper turns black
Microsoft says the August 27, 2026 Windows 11 preview update KB5120998 can cause desktop settings to fail to load, making wallpapers display as solid black and potentially resetting themes, slideshow, and other display preferences on devices running 24H2 and 25H2. Affected users may be unable to restore their custom settings, and the issue affects the optional, non-security update; if the “Get the latest updates as soon as they’re available” option is enabled, it can install automatically.