Microsoft has released the September 2026 non-security preview update KB5124010 for Windows 11 24H2 and 25H2 with 46 changes, including Bluetooth improvements and the ability to remap the Copilot button.
KB5124010 is a preview update that allows administrators and users to test Windows improvements, bug fixes, and new features before they become generally available during next month’s Patch Tuesday release.
However, unlike regular cumulative updates, monthly optional updates like KB5124010 only provide quality improvements and not security fixes.
The September 2026 Preview Update adds support for Emoji 17.0a new Open Apps Maximized accessibility setting that automatically maximizes app windows when opened, and a remote recovery management plugin to expand Windows Recovery (WinRE) management capabilities.
Microsoft also fixed an issue where the Bluetooth wireless connection could be turned off while the Bluetooth wireless control toggle still showed as “On” in Settings, as well as a bug that could cause crashes with error code 0x139 when streaming Bluetooth audio.
Additionally, microphone compatibility with certain Bluetooth Classic audio accessories and reliability and performance with LE Audio accessories have been improved.
After this preview update is deployed, users will also be able to remap the Copilot key on their Windows devices to act as a right Ctrl or context menu key via a new Windows 11 setting.
You can install the KB5124010 update by opening it Settingsclick on Windows Update, and then “Check for updates.”
As this is an optional update, you must click the “Download and install” link unless you have already checked the “Get the latest updates as soon as they are available” option, which will prompt the operating system to install them automatically.
You can also manually download and install the KB5124010 preview update from Microsoft Update Catalog.
Highlights of Windows 11 KB5124010
Once installed, this optional, non-security update updates Windows 11 25H2 and 24H2 devices to builds 26200.9550 and 26100.9550, respectively.
The September 2026 Preview Update brings many other changes, some of which are highlighted below:
- This update adds support for using slideshow wallpapers with multiple desktops so you don’t automatically switch back to Image.
- New! Additional gesture controls for precision touchpads are available in Settings > Bluetooth & devices > Touchpad.
- New! This update introduces Backup camera roll in Settings to help eligible users protect their photos with OneDrive. You can activate the function via Settings home page or Accounts You can access the page using a QR code and complete the setup on a mobile phone.
In this update, Microsoft also fixed a known issue that caused the built-in File History backup feature to fail on some Windows systems after installing the September 2026 security updates.
KB5124010 will also be removed PC to PC migrationa tool that helped users transfer their files, settings and preferences to a new Windows device. Microsoft now recommends using Windows Backup to migrate to a new PC with OneDrive.
Microsoft also reminded users that KB5124010 is the final preview update for Windows 11 24H2, with support ending in October 2026.
