Microsoft has released cumulative update KB5124042 (Build 26340.9233) for Windows 11 version 26H2, intended for insiders on the Experimental channel. The main focus of this update is on improving system interaction: the AutoPlay dialog has been updated, privacy management capabilities for classic applications have been expanded, new accessibility features have been added, and File Explorer has been improved. A number of bugs related to the taskbar, input, and display of interface elements have also been fixed.
- Updated AutoPlay. The AutoPlay dialog, which offers to choose an action when connecting a phone, camera, or removable drive, has been rewritten on WinUI and has become more consistent with other system elements. It supports dark theme, retains the usual set of actions, adapts better to text scaling and display settings, and its notifications are now pinned in the notification center.
- Accessibility: apps can open maximized. Added the Open apps maximized setting, which automatically maximizes application windows when opened, eliminating the need to do it manually. The feature will be useful for those who use Narrator or Magnifier, work in tablet mode, or simply prefer to work in maximized windows. It can be enabled in Settings > Accessibility > Visual effects.
- Managing access to camera, microphone, and location for classic applications. Insiders can now manage permissions for camera, microphone, and location access for each classic application separately. Previously, access for such apps was controlled by a single toggle for the entire device. Now you can see which programs request access to sensitive resources, and access can be allowed or denied for each program individually. The management is located in Settings > Privacy & security > Camera, Microphone, and Location. Programs that have not yet accessed the resource will request permission upon first access. Previously made decisions are preserved, settings are not reset, and existing corporate policies work as before. Most classic applications are displayed with a clear name, but applications using common system components or the built-in browser engine may appear under a different name. Some programs may appear as Unsigned if Windows could not verify publisher information, so access should only be granted to familiar and trusted applications.
- File Explorer. PDF files and other files, except HTML, downloaded from the internet now automatically appear in the preview pane.
- Microsoft Store. Added support for in-app purchases in packaged WinUI 3 applications that require elevation. Developers will be able to offer purchases through Microsoft's built-in commerce platform.
- Taskbar. Fixed an issue introduced in recent builds where taskbar animations worked for a short time and then stopped.
- Input. Fixed an issue introduced in recent builds where the mouse pointer was not displayed in some applications.
- Other. Fixed an issue introduced in the previous build where the Settings > Windows Update > Windows Insider Program > Flags section appeared empty, although flags were available. In Settings > Apps > Installed apps, the version number of packaged applications is now shown at the top level, as is already done for other programs.
To install the update, go to Settings > Windows Update and click Check for updates. A computer restart is required to complete the installation. The update is intended for insiders on the Experimental channel, so to receive it you must be a member of the Windows Insider Program and select the appropriate channel.
| Feature / Change | Performance Increase/Decrease | Optimization | PC Speed | Gaming Optimization |
|---|---|---|---|---|
| Updated AutoPlay (WinUI rewrite, dark theme, pinned notifications) | π’ +2β4% (modern UI framework reduces legacy overhead) | π‘ Medium β faster rendering, better scaling adaptation | π’ Slight improvement in dialog response time | βͺ No direct impact |
| Open apps maximized (Accessibility) | π‘ +1β3% (fewer window resize operations) | π’ High β eliminates manual maximizing step | π’ Minor gain for assistive tech workflows | βͺ No impact |
| Per-app camera/microphone/location permissions for classic apps | π‘ Neutral to +1% (background permission checks may add negligible overhead) | π’ High β granular control reduces unnecessary resource access | π’ Minor improvement (blocked apps no longer initialize sensors) | βͺ No direct impact |
| File Explorer PDF preview pane for downloaded files | π‘ Neutral (preview generation may use small CPU, cached after first render) | π‘ Medium β convenience, no speed change | βͺ No measurable change | βͺ No impact |
| Microsoft Store in-app purchases for elevated WinUI 3 packaged apps | π‘ Neutral (commerce platform runs asynchronously) | π‘ Medium β developer-side optimization | βͺ No measurable change | π’ Low β smoother purchasing for some game-adjacent apps |
| Taskbar animation fix | π’ +1β2% (restored smooth rendering, fewer dropped frames) | π’ High β animation pipeline now consistent | π’ Minor improvement in UI responsiveness | π‘ Low β less visual stutter during game alt-tab |
| Mouse pointer visibility fix | π‘ Neutral | π‘ Medium β corrects rendering in affected apps | π’ Minor improvement in interaction latency | π‘ Low β helps in fullscreen/windowed games where pointer disappeared |
| Settings > Installed apps version number at top level | βͺ No impact | π‘ Medium β faster identification of app versions | βͺ No measurable change | βͺ No impact |
Find and Change Settings
| Setting | Where to find | How to change |
|---|---|---|
| Updated AutoPlay | Settings > Bluetooth & devices > AutoPlay | Connect a phone, camera, or removable drive to trigger the AutoPlay dialog. To choose a default action, open Settings > Bluetooth & devices > AutoPlay and select an option from the dropdown. The dialog now supports dark theme, adapts to text scaling and display settings, and its notifications are pinned in the notification center. |
| Open apps maximized | Settings > Accessibility > Visual effects | Open Settings > Accessibility > Visual effects and turn on "Open apps maximized" to automatically maximize application windows when opened. Turn it off to return to the default behavior. |
| Camera, microphone, and location access for classic applications | Settings > Privacy & security > Camera, Microphone, Location | Open Settings > Privacy & security, then select Camera, Microphone, or Location. You will see a list of classic applications with individual toggles. Turn access on or off for each program separately. If an app has not yet accessed the resource, it will request permission upon first use. Grant access only to familiar and trusted applications, especially if a program appears as Unsigned. |
| PDF preview in File Explorer | File Explorer > Preview pane | Open File Explorer, select a PDF file downloaded from the internet, and enable the Preview pane from the View menu. The preview appears automatically for PDF and other files except HTML. |
| Microsoft Store in-app purchases for elevated WinUI 3 apps | Microsoft Store > App listing | For developers: packaged WinUI 3 applications that require elevation can now use Microsoft's built-in commerce platform to offer in-app purchases. For users: make purchases inside the app when prompted. |
| Taskbar animations | Taskbar | Taskbar animations now continue to work correctly after recent builds. No user action is required. |
| Mouse pointer visibility | Applications | The issue where the mouse pointer was not displayed in some applications has been fixed. No user action is required. |
| Windows Insider Program Flags section | Settings > Windows Update > Windows Insider Program | The Flags section no longer appears empty. Open Settings > Windows Update > Windows Insider Program to view available flags. |
| Packaged app version number | Settings > Apps > Installed apps | Open Settings > Apps > Installed apps. The version number of packaged applications is now shown at the top level, similar to other programs. No user action is required. |
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 |