Microsoft has deployed a fix for a critical bug in Windows 11 that caused mouse personalization settings to revert to defaults after an August preview update. Users are urged to install the September cumulative update.
- The KB5120998 August preview update caused mouse cursor and animation settings to reset.
- The issue specifically targeted non-English Windows installations due to code component failures.
- The fix is integrated into the KB5124008 September 2026 cumulative update.
Microsoft has officially addressed a frustrating bug that wiped mouse personalization settings on a subset of Windows 11 systems. The issue emerged following the installation of the KB5120998 August 2026 preview update, which was intended to enhance the Start menu, taskbar, and Windows search for versions 24H2 and 25H2.
According to numerous user reports, cursor settings and animations were automatically reverted to standard defaults. In a particularly troubling twist, users found that uninstalling the buggy update did not restore their previous settings, indicating a deeper corruption of the user profile's personalization data.
Why This Matters
BozokMedia analysis shows that this glitch highlights a systemic vulnerability in how Microsoft handles non-English locale settings. When core UI components fail to load based on language scripts, it creates a fragmented user experience. This suggests that regional testing for preview builds remains a significant blind spot in the Windows deployment pipeline.
The inability to restore settings even after an uninstall points to a failure in the registry backup process during update installation.
To remedy this, Microsoft released the KB5124008 September 2026 cumulative update. The company strongly recommends that all users install this latest security update, as it not only resolves the mouse issue but also provides critical security patches for the OS.
This is not an isolated incident of UI instability. The KB5120998 update was also linked to the erasure of custom desktop settings on various devices. Furthermore, Microsoft has recently battled issues where the Windows Recovery Environment (WinRE) disabled USB peripherals, and a recurring bug causing the mouse pointer to vanish in classic Outlook.
| Update ID | Impact | Current Status |
|---|---|---|
| KB5120998 | Mouse & Desktop Settings Reset | Buggy / Deprecated |
| KB5124008 | Bug Fix & Security Patch | Stable / Recommended |
Frequently Asked Questions
Q1: Does this bug affect all Windows 11 users?
No, it primarily affected users of non-English Windows installations who installed the August preview update.
Q2: How can I fix my mouse settings?
Navigate to Windows Update and install the September cumulative update (KB5124008) to resolve the issue.
