KB5124112


Microsoft has released cumulative update KB5124112 (Build 28120.3002) for Windows 11, version 26H1, for Insiders in the Experimental channel. The update is available through Windows Update and includes a number of improvements to the interface and system features, while also retaining a known issue with launching games.

Games protected by Easy Anti-Cheat (EAC) may fail to launch and display the error "The application was unable to start correctly (0xc000007b)." The issue has carried over from the previous build, and Microsoft continues to work on a fix.

To install via Windows Update: go to Settings > Windows Update and click Check for updates. A computer restart will be required to complete the installation.

Feature / Change Performance Gain or Loss Optimization PC Speed Gaming Optimization
Quick Settings navigation with a gamepad. The Bluetooth Quick Settings page can now be navigated using a gamepad. 🟡 Minimal (no measurable performance change) 🟡 Slight (faster access to Bluetooth settings, no system-level optimization) ⚪ No impact (navigation convenience only) 🟡 Low (helps controller users toggle Bluetooth devices faster, no FPS or latency change)
Pinning favorite apps in the Share window. The Share window (Windows Share) now allows you to pin favorite apps. ⚪ No impact (UI convenience feature) 🟡 Slight (reduces time to share files, no background optimization) ⚪ No impact (does not affect system speed) ⚪ No impact (not gaming-related)
Games protected by Easy Anti-Cheat (EAC) may fail to launch and display the error "The application was unable to start correctly (0xc000007b)." The issue has carried over from the previous build, and Microsoft continues to work on a fix. 🔴 Negative (EAC-protected games may not launch at all) 🔴 Regression (known issue carried over, not yet fixed) ⚪ No impact on general PC speed (only affects affected games) 🔴 High negative (blocks launch of many popular multiplayer games such as Fortnite, Apex Legends, Rust, and others using EAC)

Find and Change Settings

Setting Where to find How to change
Quick Settings navigation with a gamepad Settings > Bluetooth & devices Connect your gamepad via Settings > Bluetooth & devices > Add device. Open Quick Settings with Win + A and navigate the Bluetooth Quick Settings page using the gamepad controls.
Pinning favorite apps in the Share window Share window (Windows Share) Open the Share window from any app that supports sharing. Right-click or use the pin option next to an app in the list to pin it as a favorite. To unpin, use the same option again.

Official announcement on the Microsoft website.

The last 10 Windows updates:

Update Build Version Windows Channel Date
KB5124006 28000.3079 26H1 Windows 11 Preview 2026-09-11
KB5124115 26220.9472 25H2 Windows 11 Beta 2026-09-11
KB5124111 28020.2991 26H1 Windows 11 Beta 2026-09-11
KB5124112 28120.3002 26H1 Windows 11 Experimental 2026-09-11
KB5124114 26340.9482 26H2 Windows 11 Experimental 2026-09-11
KB5124010 26300.9539 26H2 Windows 11 Preview 2026-09-10
KB5125726 28120.2912 26H1 Windows 11 Experimental 2026-09-08
KB5124058 26340.9354 26H2 Windows 11 Experimental 2026-09-08
KB5124061 26220.9343 25H2 Windows 11 Beta 2026-09-08
KB5124059 28020.2904 26H1 Windows 11 Beta 2026-09-08