Microsoft has just fixed a critical bug that was causing desktop settings to be lost or reset on some Windows devices. The issue, which affected Windows 11 systems running on versions 24H2 and 25H2, wiped out wallpaper and theme settings, leaving users with a blank black screen. What’s more alarming is that this bug also had the side effect of changing mouse settings, making it impossible to restore previous configurations.
The root cause of this problem lies in the KB5120998 August preview update, which was installed on affected devices. This optional update, which requires users to click the “Download and install” link, may have been automatically applied if the “Get the latest updates as soon as they’re available” option was enabled. Despite its optional nature, this update had a significant impact on users’ desktop settings.
The issue was first reported by Microsoft last week in a Windows release health update. According to the company, attempting to manually restore customized settings did not work because the bug prevented the correct loading of settings. As a result, affected devices displayed default black backgrounds instead of custom wallpapers and themes. Moreover, mouse settings were also changed or reset, leaving users unable to recover their previous configurations.
This is not an isolated incident; Microsoft has faced similar issues in the past. In 2020, the company addressed a bug that caused desktop wallpaper functionality to break on Windows 7 systems. However, this latest issue affects newer versions of Windows and highlights the importance of thorough testing before releasing updates.
Fortunately, Microsoft has now released a patch (KB5124008) that fixes this critical bug. The company advises users to install the latest security update for their device as it contains important improvements and issue resolutions, including this one. It is essential for users to keep their systems up-to-date with the latest patches to prevent such issues from occurring.
In practical terms, users should ensure they have installed the latest Windows updates, particularly those released on September 8 (KB5124008) or later. This will not only fix the desktop settings bug but also address other critical security vulnerabilities and improvements. It’s also essential for administrators to regularly review system logs and monitor user activity to detect any potential issues related to update installations. By taking these precautions, users can minimize the risk of encountering similar problems in the future.
Source: Bleeping Computer — 2026-09-10