KB5121109


Microsoft has released cumulative update KB5121109 (Build 28120.2738) for Windows 11 version 26H1, intended for insiders on the Experimental channel. This release includes the removal of the legacy WMIC utility, the rollback of the Drag Tray feature based on user feedback, as well as several important fixes aimed at improving system stability and accessibility.

Known issues:

To install update KB5121109 (Build 28120.2738), go to Settings > Windows Update and click Check for updates. A system restart is required to complete the installation.

Feature / Change Performance Impact Optimization PC Speed Gaming Optimization
WMIC removal 🟢 Slight improvement (less legacy overhead) 🟢 System cleanup, smaller attack surface 🟡 Minimal (rarely used by consumers) ⚪ No direct impact
Drag Tray removal 🟡 Neutral (feature removed) 🟢 Reduced background code 🟡 Minimal ⚪ No impact
Settings crash fix (System > Notifications) 🟢 Improved stability 🟡 Minor resource optimization 🟢 Slightly faster UI response ⚪ No direct impact
Magnifier launch fix 🟢 Improved responsiveness 🟡 Minor 🟡 Minimal ⚪ No impact
PUBG compatibility issue (known) 🔴 Temporary performance loss for affected users 🔴 Blocked until fix 🔴 Game may not launch 🔴 Severe (PUBG unavailable)

Find and Change Settings

Setting Where to find How to change
WMIC Removal Command Prompt / Terminal WMIC is no longer available. Use PowerShell cmdlets (for example, Get-CimInstance or Invoke-CimMethod) instead. No action can restore WMIC in this build.
Drag Tray Taskbar The Drag Tray feature has been removed. There is no setting to re-enable it. Wait for a future replacement announced by Microsoft.
Settings crash under System > Notifications Settings > System > Notifications The crash has been fixed. Update to this build and open Settings > System > Notifications normally.
Magnifier launch issue Settings > Accessibility > Magnifier The launch failure has been fixed. Open Settings > Accessibility > Magnifier and turn it on using the toggle or keyboard shortcut.
PUBG: BATTLEGROUNDS compatibility Game launch (PUBG: BATTLEGROUNDS) A compatibility restriction may prevent the game from launching. Microsoft and the game developer are working on a fix. No user setting can bypass this restriction yet.

Official announcement on the Microsoft website.

The last 10 Windows updates:

Update Build Version Windows Channel Date
KB5121132 28120.2760 26H1 Windows 11 Experimental 2026-08-21
KB5124040 26220.9223 25H2 Windows 11 Beta 2026-08-21
KB5124042 26340.9233 26H2 Windows 11 Experimental 2026-08-21
KB5121106 28020.2731 26H1 Windows 11 Beta 2026-08-17
KB5121109 28120.2738 26H1 Windows 11 Experimental 2026-08-17
KB5124036 26220.9202 25H2 Windows 11 Beta 2026-08-17
KB5124038 26340.9212 26H2 Windows 11 Experimental 2026-08-17
KB5120996 28000.2796 26H1 Windows 11 Preview 2026-08-14
KB5120998 26200.9267 25H2 Windows 11 Preview 2026-08-14
KB5120240 22631.7517 23H2 Windows 11 Stable 2026-08-11