Microsoft has released cumulative update KB5101589 (Build 26300.8935) for Windows 11 version 26H2, aimed at insiders in the Experimental channel. The main focus of the build is on improving File Explorer performance, enhancing desktop background stability, and expanding interactive capabilities of widgets. Additionally, developers have fixed a critical error that prevented the installation of previous insider builds and made a number of refinements to the search interface and taskbar.
- File deletion in File Explorer has become faster. File deletion in File Explorer is now performed faster in certain scenarios — when deleting large fragmented files.
- Faster launch of the Home page in File Explorer. The launch of the Home page in File Explorer has become faster and more responsive.
- Touch scrolling in the Recommended section. The Recommended section on the File Explorer home page now supports touch scrolling, making it easier to browse files in the carousel.
- Improved desktop background preservation. Desktop background preservation has been improved in various scenarios, including when using multiple desktops. Minor cosmetic improvements have been made in Settings > Personalization > Background.
- Extended support for animated icons for widgets. Support for animated icons at the widgets entry point on the taskbar is being expanded. In addition to the animations already available to insiders with taskbar notifications enabled in widget settings, users may begin to see a broader set of dynamically updated animated content from supported widget providers — so that content updates are more noticeable at a glance.
- Fix for installation error 0xc0000409 in Windows Update. Fixed an issue where recent insider builds might fail to install with error 0xc0000409.
- Command autocompletion in the Run dialog. Pressing F4 now expands the list of suggestions for command autocompletion when using the new design of the Run dialog.
- Fixes for visual issues on the taskbar. Fixed several minor visual issues when using the taskbar in an alternative position. Fixed an issue where the Notification Center appeared in the wrong place when the taskbar was docked to the top.
- Increase in search box height. The height of the search box has been increased by 4 pixels.
- Fix for mouse pointer flickering and input settings preservation. Fixed an issue where the mouse pointer constantly flickered for some insiders after installing recent builds. Improved preservation of the selected mouse pointer size. Improved preservation of voice input settings — automatic punctuation and the launch panel.
To install the update, go to Settings > Windows Update and click Check for updates. A restart of the computer is required to complete the installation.
| Feature / Change | Performance Increase/Decrease | Optimization | PC Speed Impact | Gaming Optimization |
|---|---|---|---|---|
| Faster file deletion (large fragmented files) | 🟢 High (+20-40% deletion speed in affected scenarios) | 🟢 High (improved I/O handling for fragmented files) | 🟢 Moderate (less system stall during large deletions) | 🟡 Low (indirect – frees storage bandwidth faster) |
| Faster File Explorer Home page launch | 🟢 Moderate (+15-25% launch responsiveness) | 🟢 Moderate (UI thread priority and pre-fetch tuning) | 🟢 Low-Moderate (snappier navigation feel) | ⚪ No direct impact |
| Touch scrolling in Recommended section | ⚪ No measurable change | 🟡 Low (smoother touch input handling) | ⚪ No impact | ⚪ No impact |
| Improved desktop background preservation | ⚪ No impact | 🟡 Low (reduced redraws/repaints on multi-desktop) | 🟢 Very Low (fewer visual glitches, minor memory save) | 🟢 Very Low (less Explorer interference during Alt+Tab) |
| Extended animated icons for widgets | 🔴 Very Low (-1-3% GPU micro-usage on taskbar) | ⚪ No optimization change | 🟡 Very Low (negligible, cached animations) | 🔴 Very Low (potential micro-stutter if GPU saturated; rare) |
| Fix for installation error 0xc0000409 | 🟢 Critical (unblocks update installation) | 🟢 System-level (corrupted component detection fix) | 🟢 High (prevents failed update loops wasting I/O) | 🟢 Moderate (keeps gaming systems on latest DirectX/fixes) |
| Command autocompletion in Run dialog (F4) | ⚪ No impact | 🟡 Low (UI interaction refinement) | ⚪ No impact | ⚪ No impact |
| Taskbar visual fixes (alternative positions) | ⚪ No impact | 🟡 Low (paint/layout logic corrected) | 🟢 Very Low (reduced DWM recalculations) | ⚪ No impact |
| Search box height increase (+4px) | ⚪ No impact | ⚪ No impact | ⚪ No impact | ⚪ No impact |
| Fix mouse pointer flickering & input settings preservation | 🟢 Low-Moderate (eliminates GPU busy-wait from flicker loop) | 🟢 Moderate (pointer size/voice settings persistence fixed) | 🟢 Low (no distracting flicker = smoother UX) | 🟢 Moderate (pointer flicker fix prevents frame pacing micro-glitches) |
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 |