Windows 11 KB5120998 Update Resets Desktop Settings and Changes Wallpapers to Black
Microsoft has confirmed that the Windows 11 KB5120998 August 2026 Preview update can cause some devices to lose or reset their desktop settings. Affected users report that their wallpaper changes to a solid black background after installing the update.
Several users reported the issue on Reddit, including cases where a customized wallpaper was automatically replaced with a black background after the Windows update. Microsoft’s confirmation followed these reports: initial report, user discussion, wallpaper report, and black background report.
The known issue affects devices running Windows 11 version 24H2 and Windows 11 version 25H2. In addition to changing the desktop wallpaper, the bug can reset the desktop theme, slideshow settings, contrast themes, and other personalization options.
“When you install the Windows update released on August 27, 2026 (KB5120998) or later, some Windows desktop settings fail to load and the desktop background appears solid black,” Microsoft said in a Windows release health update. “Other desktop settings may be affected, such as slideshow settings and contrast theme.”
According to Microsoft, users may be unable to restore their customized desktop settings on affected devices. Manually selecting a new wallpaper or changing other personalization options may not resolve the problem.
“Attempts to manually restore customized settings will not work on affected devices because this issue prevents the settings from loading correctly, regardless of the setting’s value. In this case, the default black background is used instead,” Microsoft added.
Microsoft released KB5120998 on August 27, 2026, as an optional non-security update for Windows 11 versions 24H2 and 25H2. The preview update includes improvements to the Start menu, taskbar, and Windows Search, but it also introduces the desktop personalization bug and may reset mouse settings.
Because KB5120998 is an optional update, Windows 11 users generally need to open Windows Update and click Download and install to apply it. However, the update may install automatically when the Get the latest updates as soon as they’re available option is enabled.
Users who have not installed KB5120998 may want to delay the optional update until Microsoft provides a fix. Those already affected should monitor Microsoft’s Windows release health documentation for additional guidance and a permanent resolution.
Microsoft previously addressed a similar wallpaper problem in February 2020 with the KB4539602 update. That issue caused Windows 7 wallpapers configured in “stretch” mode to appear as a blank black screen.
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Source: www.bleepingcomputer.com