Microsoft released the optional September 2026 preview update, KB5124010, for Windows 11, which introduces new features like Emoji 17, Copilot-key remapping, and fixes for Bluetooth and camera issues. However, it also poses significant risks, particularly for machines with Credential Guard, as it can disrupt the domain trust relationship, preventing users from signing in. Additionally, some USB Audio Class 1.0 devices may encounter Error Code 10 after this update, compounding existing audio issues. While the update offers enhancements, users in domain environments should test it thoroughly before deployment, as these bugs will be addressed in the upcoming October Patch Tuesday build

Windows 11 KB5124010: September Preview Update Details and Known Issues

Microsoft shipped KB5124010, an optional September 2026 preview update for Windows 11 25H2 (build 26200.9550) and 24H2 (build 26100.9550), on September 22. It delivers a batch of new features including Emoji 17, Copilot-key remapping, touchpad gestures, and Bluetooth and camera fixes. The catch is that it can break the domain trust relationship on Credential Guard–protected machines, locking out interactive domain sign-ins in environments below Windows Server 2025's Domain Functional Level. A second issue leaves some USB Audio Class 1.0 devices throwing Error Code 10, and both will carry into the October 13 Patch Tuesday build.

Windows 11 KB5124010: September Preview Update Details and Known Issues @ NT Compatible