Microsoft has unveiled the KB5124010 September 2026 non-security preview update for Windows 11 versions 24H2 and 25H2, introducing a total of 46 enhancements. Among these updates are notable improvements to Bluetooth functionality and the newly added capability to remap the Copilot key.
This preview update serves as a testing ground for administrators and users, allowing them to experience upcoming Windows enhancements, bug fixes, and features prior to their official rollout during the next month’s Patch Tuesday. It is important to note that, unlike standard cumulative updates, this optional monthly update focuses solely on quality improvements and does not include any security fixes.
The September 2026 update brings several exciting features, including:
- Support for Emoji 17.0, enhancing user expression.
- A new accessibility setting titled “Open apps maximized”, which automatically maximizes app windows upon opening.
- A recovery remote management plug-in designed to extend Windows Recovery (WinRE) management capabilities.
Additionally, Microsoft has addressed a critical issue where the Bluetooth radio could be inadvertently turned off while the settings still indicated it was on. Users will also benefit from fixes related to Bluetooth audio streaming, specifically resolving crashes linked to error code 0x139. Improvements have been made to microphone compatibility with certain Bluetooth Classic audio accessories, as well as overall reliability and performance enhancements for LE Audio accessories.
With the installation of this preview update, users can now remap the Copilot key on their Windows devices through a new setting, allowing it to function as either the Right Ctrl or Context Menu key.
To install the KB5124010 update, users should navigate to Settings, select Windows Update, and click on “Check for Updates.” As this is an optional update, users will need to click the “Download and install” link unless they have enabled the “Get the latest updates as soon as they’re available” option, which will facilitate automatic installation.
For those who prefer a manual approach, the KB5124010 preview update can also be downloaded directly from the Microsoft Update Catalog.
Windows 11 KB5124010 highlights
Upon installation, this optional non-security update will elevate Windows 11 25H2 and 24H2 devices to builds 26200.9550 and 26100.9550, respectively. The September 2026 preview update encompasses a range of additional changes, with some key highlights including:
- The ability to use slideshow wallpapers across multiple desktops, preventing automatic reversion to Picture mode.
- New! Enhanced gesture controls for precision touchpads, accessible via Settings > Bluetooth & devices > Touchpad.
- New! Introduction of Camera roll backup in Settings, enabling eligible users to safeguard their photos with OneDrive. This feature can be activated from the Settings Home or Accounts page, with setup completed on a mobile device using a QR code.
Furthermore, Microsoft has rectified a known issue that caused the built-in File History backup feature to malfunction on certain Windows systems following the installation of the September 2026 security updates. It is worth noting that KB5124010 also removes the PC-to-PC Migration tool, which previously assisted users in transferring files, settings, and preferences to new Windows devices. Microsoft now advocates the use of Windows Backup for migrating to a new PC via OneDrive.
As a final note, Microsoft has indicated that KB5124010 marks the last preview update for Windows 11 24H2, which is set to reach its end of support in October 2026.
