Windows 11 KB5120998 Update Resets Mouse Settings

Microsoft has acknowledged a bug within its Windows 11 KB5120998 update that causes user-defined mouse settings to revert to their default configurations. This issue was confirmed by the company following reports from users who experienced the problem after installing the non-security preview update released in August 2026. The update, identified by the KB number KB5120998, is intended to provide system enhancements and bug fixes, but instead introduced this specific regression affecting mouse customization. Users who have applied this update may find that their preferred mouse sensitivity, pointer speed, scrolling direction, or other personalized settings are no longer active, requiring them to reconfigure these options. This unexpected behavior disrupts the user experience for individuals who rely on specific mouse configurations for productivity or comfort. The company has not yet provided a timeline for a fix, but it is expected that a subsequent update will address this mouse setting reset. In the interim, affected users are advised to reapply their preferred mouse settings after the update has been installed. This incident highlights the ongoing challenges in ensuring seamless updates for complex operating systems like Windows 11, where even minor updates can sometimes introduce unintended consequences. The KB5120998 update is part of Microsoft's regular release cadence for Windows 11, which includes cumulative updates and optional preview builds designed to test upcoming changes before their wider deployment. The non-security nature of this particular update means it does not address critical security vulnerabilities but focuses on feature enhancements and stability improvements. However, the introduction of a bug that affects fundamental user interface elements like mouse settings is a notable oversight. Microsoft's support channels and official Windows release notes are expected to provide further details and guidance as the company works towards a resolution. Users experiencing this issue are encouraged to report it through the Feedback Hub application within Windows 11 to aid Microsoft's diagnostic efforts. The company's commitment to user experience means that such issues are typically prioritized for resolution in subsequent patch releases. The specific impact of this bug varies depending on the user's prior customization of their mouse settings, with those who have made extensive adjustments being more likely to notice the change. This situation underscores the importance of thorough testing before the broad release of any software update, particularly for an operating system used by millions of individuals worldwide. The KB5120998 update is a preview release, meaning it is made available to users who opt-in to receive early access to non-security updates. This allows Microsoft to gather feedback and identify potential issues before the changes are rolled out to all Windows 11 users via the monthly Patch Tuesday updates. The company's proactive approach to soliciting feedback through channels like the Feedback Hub is crucial for identifying and rectifying such problems efficiently. The current lack of a definitive fix suggests that the issue may require a more comprehensive solution than a simple hotfix, potentially necessitating inclusion in the next cumulative update cycle.