Microsoft has officially released Windows 11 preview build 26100.9539 to users in the Release Preview Channel. This update introduces built-in remapping for the hardware Copilot key, along with broader usability and accessibility improvements across the operating system.
Alongside the ability to reassign hardware actions, the preview build incorporates the Emoji 17.0 collection, file safety handling tweaks within File Explorer, and general performance updates across multiple system components.
Windows 11 Release Preview Builds 26100.9539 and 26200.9539 Roll Out
The latest update is rolling out simultaneously as Build 26100.9539 for Windows 11, version 24H2, and Build 26200.9539 for version 25H2 under cumulative update package KB5124010. Microsoft is distributing the release through two distinct deployment phases: a gradual rollout phase for early feature testing on eligible devices, followed by a broader general rollout to all Release Preview channel participants.
This dual-phase delivery model ensures system stability while allowing engineers to collect real-world telemetry before deploying features to the general public. While previous testing focused heavily on underlying kernel adjustments, this update brings visible end-user features that address common customer requests.
Native Copilot Key Remapping in Settings
The headline feature in this build is native support for remapping the dedicated Copilot key found on newer AI PCs and modern laptop keyboards. Ever since device manufacturers began introducing hardware buttons designated for Copilot, many users expressed frustration over losing original key assignments, such as the Right Ctrl or Context Menu keys.
In response to feedback regarding altered workflows, Microsoft added a configuration section directly inside the Settings application under Settings > Bluetooth & devices > Keyboard. Users can now easily reassign the Copilot key to function as either the Right Ctrl key or the Context Menu (Application) key, effectively restoring traditional layout behavior for shortcut-heavy workflows and screen reader software.
For users who prefer deeper customization options, third-party utilities and tools like Microsoft PowerToys continue to provide alternative key binding capabilities. However, providing a clean built-in mechanism eliminates the requirement to maintain active background software just to change a physical key's behavior.
Emoji 17.0 Integration and Visual Refinements
Build 26100.9539 also brings full support for the Emoji 17.0 standard to Windows 11. Users can access new additions, such as the distorted face, fight cloud, and hairy creature emojis, by launching the native emoji picker via the Win + Period (.) keyboard shortcut.
Beyond brand-new characters, Microsoft refined existing glyph designs to ensure visual consistency across cross-platform messaging environments. Updated icons include redesigned versions of the saluting face, face with peeking eye, goose, lotus, and kissing cat emojis.
File Explorer Preview Pane and System Enhancements
File management sees substantial usability improvements in this update. Microsoft modified how the File Explorer preview pane handles web-downloaded content to bolster security without unnecessarily slowing down productivity.
Handling Downloaded Files in Preview Pane
When selecting web-sourced HTML files, the File Explorer preview pane now prompts users with a new Preview anyway button, requiring explicit acknowledgment before rendering external markup. Conversely, non-HTML file formats like downloaded PDF documents now preview automatically without requiring additional confirmation steps.
Additionally, File Explorer Home now remembers whether collapsible sections were left expanded or collapsed between user sessions, ensuring layout preferences remain intact. Microsoft also resolved a bug where clicking near the right margin of the File Explorer address bar accidentally cleared typed text when entering edit mode, alongside improvements to cloud file thumbnail reliability within the Details pane.
These changes complement ongoing shell updates seen in recent months, such as updates like the Windows 11 KB5120998 update that brought user-interface flexibility back to core navigation elements.
Tips Widget and Additional Accessibility Options
For system customization and daily usage, the update integrates a new Tips widget to help users discover hidden shortcuts and new operating system capabilities. Power management logic has also been streamlined; changes configured inside the modern Settings app now propagate reliably across all legacy power plan profiles, covering sleep timers, lid-close actions, and power button configurations.
Accessibility experiences receive meaningful updates as well. Network connectivity options within the Windows Recovery Environment (WinRE) now support Wi-Fi networks, enabling troubleshooting and system recovery without requiring a wired Ethernet connection. These network-level recovery capabilities align with broader maintenance updates like the recent September Patch Tuesday KB5124008 update aimed at optimizing long-term platform resilience.
Availability and Deployment Timeline
Windows Insiders currently enrolled in the Release Preview Channel can install Build 26100.9539 or 26200.9539 by navigating to Settings > Windows Update and checking for new updates. If the gradual rollout option is toggled on, new features will unlock progressively as device validation checks complete.
Assuming testing passes without major blockership bugs, these features, including native Copilot key remapping and File Explorer tweaks, are expected to reach the stable version of Windows 11 in an upcoming monthly cumulative update.
