Microsoft confirms mouse bug in Windows 11 preview update only hits non-English PCs

Key points

• Microsoft released the KB5120998 optional preview update for Windows 11 on 27 August 2026.
• Users reported mouse cursor and animation settings being reset to defaults after installing it.
• Microsoft confirmed on Tuesday that only non-English Windows 11 installations are affected.
• The update is optional, but installs automatically if "Get the latest updates as soon as they're available" is switched on.
• A separate issue in the same update resets desktop settings on some machines.

Microsoft has narrowed down a curious little bug in its latest Windows 11 preview update. If your computer runs in French, German, Japanese or almost any language other than English, installing KB5120998 may quietly wipe out your mouse cursor choices. If it runs in English, you are fine.

The update landed on 27 August 2026 as an optional preview, meaning a test build of next month's fixes that users can install early. It brings tweaks to the Start menu, taskbar and Windows search on Windows 11 versions 25H2 and 24H2.

A day later, the complaints started. People said their custom cursors and cursor animations had reverted to Windows defaults, and that reapplying the old settings simply did not stick.

What exactly is going wrong?

The update overwrites personal mouse settings on non-English systems, and the operating system then refuses to load the user's chosen cursor. Microsoft says the code that handles these settings fails in non-English locales, so Windows falls back to a standard cursor instead.

"Following installation of Windows updates released August 27 2026 (KB5120998) and later, mouse personalization settings are being reverted to certain standard settings," the company wrote on its Windows release health dashboard. "This includes cursor and cursor animations that are selected in the Mouse Properties options under Windows."

In a follow-up on Tuesday, Microsoft added: "Our investigation indicates that this issue is caused by code components used in non-English Windows installations. In impacted locales, these settings will fail to load, causing a default to be used instead."

So it is a localisation bug, not a security flaw. No data leaks, no attacker in the picture. Just a cosmetic setting that will not stay put.

Do I need to install this update?

Probably not. KB5120998 is optional and non-security, which means it contains no fixes for hacking risks and you can safely skip it. The catch: if you have switched on "Get the latest updates as soon as they're available" in Windows Update, your machine will pull it down on its own.

For anyone running Windows in a language other than English who values a custom pointer, waiting for the fixed version is the sensible call. First reported by BleepingComputer, the issue has not yet been given a patch date.

The update at a glance

A rough run for Windows mouse handling

This is not the first pointer problem Microsoft has faced this year. In October the company shipped an emergency fix for a bug that disabled USB mice and keyboards inside the Windows Recovery Environment, the safe-mode toolkit used to repair a broken PC.

More recently, Microsoft said it was looking into a fault that makes the mouse cursor vanish in classic Outlook when hovered over the app's interface. And on Wednesday, the company acknowledged a second problem inside KB5120998 itself: some users are losing their desktop settings after installing it.

None of these are security incidents. They are quality-control slips. Still, when a preview update touches something as basic as the mouse and the desktop, it is a reminder that "optional" updates earn that label for a reason. Multi-factor authentication would not have helped here, and for once that is because nobody is being attacked. It is just Windows tripping over its own translations.