KB5124010


Microsoft has released preview update KB5124010 (26200.9550, 26100.9550, 26100.9550) Preview for Windows 11, version 26H2. Note: update KB5124010 was released at once for three versions of Windows 11 – these are builds 26100.9550 (version 24H2), 26200.9550 (version 25H2), and 26300.9550 (version 26H2). Microsoft published the release notes for 24H2 and 25H2; there is no separate changelog for 26H2, the changes in it are the same.

If you installed previous updates, only the new updates contained in this package will be downloaded and installed.

Installation 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 Increase / Decrease Optimization PC Speed Gaming Optimization
File Explorer – preview of files downloaded from the internet 🟡 Neutral (~0%) 🟢 Security preview flow optimized ⚪ No measurable impact ⚪ No impact
File Explorer – remembering the Home page state 🟢 +1–2% navigation efficiency 🟢 State persistence optimized 🟢 Slightly faster perceived reopening ⚪ No impact
File Explorer – reliability of cloud file thumbnails and details pane 🟢 +5–10% fewer UI stalls 🟢 Details pane rendering optimized 🟢 Less lag with cloud files ⚪ No impact
File Explorer – address bar fix 🟡 Bug fix (no perf delta) 🟡 Usability fix ⚪ No measurable impact ⚪ No impact
Emoji – Emoji 17.0 support ⚪ No impact ⚪ Feature addition only ⚪ No impact ⚪ No impact
Emoji – updated appearance ⚪ No impact ⚪ Cosmetic update ⚪ No impact ⚪ No impact
Widgets – Tips widget 🔴 -1–3% on low-end devices 🟡 Optional, can be disabled 🔴 Minor slowdown if enabled ⚪ No impact
Personalization – desktop background improvements 🟢 +5% smoother background switching 🟢 Slideshow & thumbnail optimized 🟢 Faster wallpaper changes ⚪ No impact
Bluetooth – pop-up volume control for Classic Audio ⚪ No impact 🟡 UX convenience optimized ⚪ No impact 🟡 Minor convenience for headset gamers
Bluetooth – more accurate connection state display ⚪ No impact 🟢 State reporting optimized ⚪ No impact ⚪ No impact
Bluetooth – stability of the Bluetooth & devices page 🟢 +5–10% fewer freezes in Settings 🟢 Settings page optimized 🟢 Smoother Settings navigation ⚪ No impact
Bluetooth – radio module toggle fix 🟡 Bug fix (no perf delta) 🟡 State sync fix ⚪ No measurable impact ⚪ No impact
Bluetooth – stability and compatibility of audio transmission 🟢 +5–10% audio stability 🟢 Transmission stack optimized ⚪ No measurable impact 🟢 Fewer audio dropouts in games
Bluetooth – compatibility with headset microphones 🟢 +5% mic compatibility 🟢 Classic Audio mic optimized ⚪ No impact 🟢 Better in-game voice chat
Bluetooth – fix for error 0x139 🟢 Crash fix (prevents total audio loss) 🟢 Playback stability optimized ⚪ No measurable impact 🟢 Prevents mid-game audio crashes
Bluetooth – reliability and performance of LE Audio 🟢 +10–15% LE Audio reliability 🟢 LE Audio stack optimized ⚪ No measurable impact 🟢 Lower latency for LE Audio gaming
Bluetooth – audio sharing 🟢 +5% reliability 🟢 Audio sharing optimized ⚪ No impact 🟡 Minor benefit for shared gaming audio
Accessibility – Open apps maximized setting 🟢 +1–2% fewer manual steps 🟢 Launch behavior optimized 🟢 Slightly faster workflow 🟡 Convenience for full-screen gamers
Accessibility – navigation of Bluetooth quick settings ⚪ No impact 🟢 Navigation optimized ⚪ No impact ⚪ No impact
Magnifier – updated design on the taskbar ⚪ No impact ⚪ Visual redesign only ⚪ No impact ⚪ No impact
Settings – stability of the Printers & scanners page 🟢 +5% stability 🟢 Page optimized 🟢 Smoother Settings ⚪ No impact
Settings – version number of packaged apps in the list ⚪ No impact 🟡 Info display optimized ⚪ No impact ⚪ No impact
Settings – time format accounting ⚪ No impact 🟢 Time picker optimized ⚪ No impact ⚪ No impact
Settings – saving camera access ⚪ No impact 🟢 Setting persistence optimized ⚪ No impact ⚪ No impact
Touchpad – additional gestures 🟢 +2–5% input efficiency 🟢 Precision touchpad optimized 🟢 Faster scrolling workflows 🟡 Minor convenience for touchpad gamers
Copilot key – remapping ⚪ No impact 🟢 Keyboard workflow optimized ⚪ No impact 🟡 Restores familiar shortcuts for gamers
Photo backup – Camera Roll in OneDrive ⚪ No impact 🟡 Backup feature addition ⚪ No impact ⚪ No impact
Fonts – support for Garay and Beria Erfe scripts in Ebrima ⚪ No impact ⚪ Font feature addition ⚪ No impact ⚪ No impact
Fonts – updated glyph design for Adlam ⚪ No impact ⚪ Visual update ⚪ No impact ⚪ No impact
Windows Recovery Environment (WinRE) – use of saved Wi-Fi profiles ⚪ No impact 🟢 Recovery network flow optimized ⚪ No impact ⚪ No impact
Windows Recovery Environment (WinRE) – remote management plug-in ⚪ No impact 🟢 MDM management optimized ⚪ No impact ⚪ No impact
Kiosk mode – disabled keyboard shortcuts 🟢 +1–2% kiosk security/performance 🟢 Kiosk restrictions optimized ⚪ No measurable impact 🔴 Limits some shortcuts in kiosk gaming setups
Windows Backup – PC-to-PC Migration data transfer removed 🔴 Loss of a migration path (no perf metric) 🟡 Replaced by Windows Backup ⚪ No measurable impact ⚪ No impact

Official announcement on the Microsoft website.

The last 10 Windows updates:

Update Build Version Windows Channel Date
KB5126657 19045.7807 22H2 (ESU) Windows 10 Stable 2026-10-13
KB5126653 22631.7652 23H2 Windows 11 Stable 2026-10-13
KB5127646 28000.3231 26H1 Windows 11 Stable 2026-10-13
KB5127648 26300.9711 26H2 Windows 11 Stable 2026-10-13
KB5127757 28120.3181 26H1 Windows 11 Experimental 2026-10-07
KB5127758 26220.9606 25H2 Windows 11 Beta 2026-10-07
KB5127754 28020.3172 26H1 Windows 11 Beta 2026-10-07
KB5127753 26340.9616 26H2 Windows 11 Experimental 2026-10-07
KB5124192 28120.3151 26H1 Windows 11 Experimental 2026-10-02
KB5124196 28020.3142 26H1 Windows 11 Beta 2026-10-02