Windows 11 KB5070311 (26200.7309 / 26100.7309) explained

KB5070311 is the November 2025 cumulative preview update for Windows 11 version 24H2 and 25H2. It moves 25H2 to build 26200.7309 and 24H2 to build 26100.7309, and it is strictly optional: nothing installs unless you trigger it from Windows Update or apply the standalone .msu package.

The update is split between gradual feature rollouts (mostly UI and AI-facing changes) and a smaller set of fixes that land immediately. It also carries a servicing stack update (KB5071142) and a few known issues you should be aware of before installing it on production machines.

Which Windows 11 versions get KB5070311

KB5070311 targets:

• Windows 11 version 24H2 (all editions) — build 26100.7309
• Windows 11 version 25H2 (all editions) — build 26200.7309

You can confirm your version with winver (press Win + R, type winver, and press Enter).

The package is large by cumulative-update standards: around 4.3GB on x64 and 3.9GB on arm64. Installation typically requires one reboot.

How to install KB5070311 (Windows Update and offline .msu)

Install from Windows Update

KB5070311 appears under optional updates, and it only offers itself if you are already on 24H2 or 25H2.

Step 1: Open Settings > Windows Update.

Step 2: Turn on Get the latest updates as soon as they’re available if you want preview builds like this one.

Step 3: Select Download & install next to 2025-11 Preview Update (KB5070311) when it appears.

Once installation completes, restart to move to build 26100.7309 or 26200.7309.

Install the offline .msu from Microsoft Update Catalog

For machines without direct internet access or where you prefer to stage updates yourself, KB5070311 is available as a standalone .msu package from the Microsoft Update Catalog at catalog.update.microsoft.com.

There are separate downloads for:

KB5070311 is bundled with a prerequisite (KB5043080) in some servicing scenarios. When installing via the Catalog, there are two supported approaches.

Method 1: Let DISM handle prerequisites automatically

Step 1: Download the relevant Windows11.0-KB5070311-*.msu file and any prerequisite MSUs into a single folder, for example C:\Packages.

Step 2: Open an elevated Command Prompt.

DISM /Online /Add-Package /PackagePath:C:\Packages\Windows11.0-KB5070311-x64.msu

Step 3: Restart the PC when prompted.

DISM scans the folder in /PackagePath and applies any required prerequisite MSUs in the necessary order.

Method 2: Install MSUs one by one, in order

If you prefer explicit control, install each .msu individually:

• windows11.0-kb5043080-x64_953449672073f8fb99badb4cc6d5d7849b9c83e8.msu
• windows11.0-kb5070311-x64_199ed7806a74fe78e3b0ef4f2073760000f71972.msu

You can apply them either with DISM:

DISM /Online /Add-Package /PackagePath:C:\Packages\windows11.0-kb5043080-x64_9534....msu
DISM /Online /Add-Package /PackagePath:C:\Packages\windows11.0-kb5070311-x64_199e....msu

or by double-clicking each file to open Windows Update Standalone Installer (wusa.exe) and following the prompts.

For updating offline media, the same commands work against a mounted image using /Image:<mountdir> instead of /Online.

New dark mode behavior and File Explorer changes

More consistent dark mode in system dialogs

One of the most visible changes in KB5070311 is the treatment of File Explorer dialogs when you run Windows in dark mode. Operation dialogs such as:

• Copy and move progress windows
• Delete file and delete folder confirmations
• “File In Use” and similar error dialogs
• Skip/replace/choose file confirmations

now follow the dark theme more reliably, with dark backgrounds, updated progress bars, and dark-themed charts for operations that show throughput or item counts. The goal is to eliminate the bright, legacy-style dialogs that previously appeared even with the system theme set to Dark.

These updates also apply to various error and confirmation dialogs, making them visually consistent with the rest of the shell.

Simplified File Explorer context menu

KB5070311 also introduces a new simplified context menu in File Explorer. Common actions such as Share, Copy, and Move are grouped into a single, more organized menu, reducing clutter and making keyboard and assistive-technology navigation more predictable.

This context menu redesign is a gradual rollout. Even after installing the update, not every device will see it immediately; feature flagging controls how quickly it appears.

Other File Explorer fixes

Alongside the visual work, KB5070311 repairs several Explorer issues:

• Video thumbnails may fail to appear when files contain certain EXIF metadata.
• An unexpected toolbar can sometimes show up in the File Explorer window.
• When right-clicking a file, the icon next to the Open entry can appear as a generic placeholder rather than the default app for that file type.

All three are addressed in this update.

Start menu and search: size and dark theme alignment

For devices with the new Start menu design (currently rolled out to a subset of Windows 11 24H2/25H2 users), KB5070311 adjusts the Windows Search panel so its height matches the Start menu. The change is purely visual but fixes the jarring transition where Search previously opened as a noticeably shorter surface.

If the refreshed Start menu is not yet enabled on a system after installing this update, that is expected. Microsoft is explicitly gating it behind a gradual rollout, independent of whether the build or KB is present.

Advanced Settings: new Virtual Workspaces page

KB5070311 adds a dedicated Virtual Workspaces page under Settings > System > Advanced. This consolidates enable/disable switches for virtualization-related features that used to live only in the old “Turn Windows features on or off” dialog.

From Virtual Workspaces, you can control components such as:

• Hyper-V (including management tools and hypervisor)
• Windows Sandbox
• Virtual Machine Platform
• Containers and guarded host (shielded VMs)
• Windows Hypervisor Platform

This doesn’t introduce new capabilities so much as surface them in a more discoverable and modern UI, while still wiring into the same underlying optional feature infrastructure.

Gaming changes: full screen experience for handhelds

The full screen experience (FSE) for handheld gaming devices is expanded in KB5070311. Initially limited to ASUS ROG Ally hardware, the mode is now available on more Windows 11 handhelds.

FSE provides a console-style shell centered around the Xbox app. It minimizes background activity and hides much of the traditional desktop environment, with the aim of:

• Reducing frame-time spikes caused by desktop processes
• Simplifying navigation with controllers
• Providing a consistent home screen for launching games

You turn it on from Settings > Gaming > Full screen experience, where you can set Xbox as the “home app” for that mode and choose whether your handheld boots directly into the full screen shell.

Copilot and AI-related features

Taskbar: share an app window directly to Copilot

On systems with Copilot, KB5070311 adds a “Share with Copilot” affordance to taskbar thumbnails. When you hover over an app icon and see its preview, you can send that app’s current content into Copilot for analysis, similar to how screen sharing works in Microsoft Teams.

Copilot Vision then inspects the shared window and responds in context—useful for summarizing documents, explaining charts, or generating responses based on what is currently on-screen.

Copilot+ PCs-only: Settings agent, Click to Do, and camera updates

Devices that meet the Copilot+ PC hardware requirements gain several extra capabilities tied to this update:

• Agent in Settings — Search in Settings shows more results with a scrollable list, and “Recommended settings” exposes inline agent actions for recently changed options. If a setting cannot be adjusted further, a dialog explains why and offers alternatives.
• Click to Do — The context menu has been redesigned for clarity, with quick actions like Copy, Save, Share, and Open. When a large image or table appears on screen, the menu can open automatically to surface relevant actions.
• Camera / Windows Studio Effects — Studio Effects (background blur, eye contact, etc.) can now be applied to an additional camera, such as a USB webcam or a rear laptop camera. Configuration lives in Settings > Bluetooth & devices > Cameras.
• Windows Search and Photos — AI-categorized photos from the Microsoft Photos app become searchable through Windows Search using semantic queries.

The update also bumps several internal AI components (Image Search, Content Extraction, Semantic Analysis, Settings Model) to version 1.2511.1196.0. These components only install and activate on Copilot+ PCs; they are dormant on standard Windows 11 systems.

Other shell and settings changes

Desktop Spotlight and Widgets

Two smaller UX changes land in this build:

• Desktop Spotlight — When Spotlight is the desktop background, the right-click menu on the desktop includes Learn more about this background and Next desktop background, bringing it closer to the lock screen Spotlight experience.
• Widgets — You can choose a default dashboard in Widget Board settings. When live weather is visible, opening the board now shows the first dashboard in the navigation bar instead of the most recently used one. Dashboard icons also display numeric badges reflecting unseen alerts; the badges clear when you leave that dashboard.

Input and keyboard

On supported hardware, two input-related improvements show up:

• Pen haptics — Pens with haptic motors provide subtle tactile cues when interacting with key UI affordances, such as the close button or when snapping and resizing windows.
• Keyboard backlight — HID-compliant keyboards with backlighting benefit from refined behavior that keeps keys readable in low light while modulating brightness to conserve power.

Settings app refinements

Several longstanding Control Panel items move into Settings, and a few issues are fixed:

• Keyboard “character repeat delay and rate” and “cursor blink rate” now live under Settings > Accessibility > Keyboard and Settings > Accessibility > Text cursor, respectively.
• The About page in Settings is reorganized so device specs and related links are grouped more coherently, with quick access to storage and other system settings.
• A bug that can make Settings unresponsive when navigating to Network & Internet is fixed.
• Another issue where the Settings search bar could overlap the window controls in the title bar is resolved.
• For some users, a new OneDrive icon appears on Settings > Accounts > Homepage to surface subscription and cloud status more clearly.

Recovery and Quick Machine Recovery (QMR)

Quick Machine Recovery is a relatively new capability for recovering from failures that leave a PC unable to boot normally. KB5070311 extends this behavior with a one-time scan on systems where both of these are enabled:

• Quick machine recovery
• Automatically check for solutions

During that scan, QMR looks for known fixes that can be applied automatically. If none are available, it explicitly directs you to other recovery options rather than stopping without guidance.

Display, graphics, and Windows on Arm Prism improvements

Three display-related fixes land in this update:

• High-resolution displays can stutter when apps query monitors for their full list of supported modes. Performance in this scenario is improved to reduce or eliminate those micro-stutters.
• On some all-in-one PCs, adjusting the brightness slider can cause brightness to snap back to its original value. That behavior is corrected.
• Certain games can mis-detect a valid GPU and display “Unsupported graphics card detected” despite supported hardware. That detection path is fixed.

On Windows on Arm devices, the Prism emulation layer is updated to support applications that rely on AVX and AVX2 instruction sets, plus related extensions such as BMI, FMA, and F16C. This widens the range of x64 applications that run correctly under emulation on Arm-based PCs.

Taskbar, system tray, and Windows Share

Beyond the Copilot integration, the taskbar picks up:

• New hover animations for grouped taskbar icons, where sliding across thumbnails shows a smooth preview transition.
• A fix for the “Automatically hide the taskbar” setting unexpectedly turning off after a message about a toolbar already being hidden on that side of the screen.
• A fix for voice access misbehaving when you try to interact with taskbar elements using numbered overlays.
• A correction for taskbar icons scaling down even when there’s ample space.

Windows Share gets more capable as well, though some of this is gated by geography and rollout state:

• Drag tray in the share UI now supports multi-file sharing, surfaces more relevant target apps, and allows quick moves into chosen folders. Drag tray can be toggled under Settings > System > Nearby sharing.
• OneDrive file links can be shared through other apps directly from the “Copy link” action in the share window, under Share using. This requires a signed-in Microsoft account and is not available in the European Economic Area.

Security and reliability fixes

Several under-the-hood issues are addressed in the “normal rollout” portion of the update, which does not depend on feature flags.

• Local Security Authority Subsystem Service (LSASS) — An access violation that can destabilize LSASS is fixed. LSASS failures typically lead to forced sign-outs or system restarts, so stabilizing it is important for domain-joined and credential-heavy scenarios.
• Notifications and explorer.exe — On some systems, particular notifications can hang explorer.exe and leave the taskbar unresponsive. That is resolved.
• Search indexer and SMB — File Explorer can fail to search certain SMB shares after recent updates. KB5070311 restores search functionality in those cases.
• Privacy & Security pages in Settings — Navigating to Microphone, Camera, or Location under Settings > Privacy & Security can cause Settings to close. That crash is fixed.
• Smart cards — Signing in with ECC Smart Card Logon Credential can unexpectedly trigger STATUS_NOT_SUPPORTED (0xc00000bb); the update removes that failure mode.
• Lock and sign-in screens — First sign-in to a new account can be unusually slow, and a memory leak when the lock screen is set to slide show can affect performance over time. Both are addressed.

Known issues in KB5070311

File Explorer white flash in dark mode

There is one notable regression that matters if you live in dark mode.

After installing KB5070311, opening File Explorer with dark mode enabled can briefly show a white screen before the window renders its contents. The same “flashbang” effect can also occur when you:

• Navigate to or from Home or Gallery (including launching directly to Home)
• Create a new tab
• Toggle the Details pane
• Select More details while copying files

There is no documented workaround beyond temporarily accepting the behavior or rolling back the update. The issue is acknowledged and slated for a future fix.

Missing password icon on the lock screen

Systems that installed the August 29, 2025 non-security preview update (KB5064081) or any later build may see another lingering UI glitch: the password icon on the lock screen’s sign-in options carousel can disappear.

Functionally, the option is still there. Hovering in the area where the icon should be reveals a clickable target; selecting it opens the password field, and sign-in proceeds normally. The problem is visual rather than functional, but it can be confusing for users who rely on the icon to switch sign-in methods.

Servicing stack update (KB5071142)

Alongside the main cumulative update, Windows 11 24H2 receives servicing stack update KB5071142, version 26100.7295. The servicing stack is the component that actually installs updates; keeping it current reduces the risk of update failures, odd Windows Update error codes, or partially applied cumulative packages.

Servicing stack updates are baked into the combined SSU+LCU package and cannot be removed once installed. Running wusa.exe /uninstall against the combined package does not work; to roll back only the latest cumulative update portion, you must use DISM /Online /Remove-Package with the specific LCU package name returned by DISM /Online /Get-Packages.

For most users, KB5070311 is primarily about dark mode consistency, new shell polish, and a handful of targeted fixes. If you can live with the temporary File Explorer white-flash issue and want the newer UX, it is a reasonable preview to install; otherwise, the same changes will be folded into a future mandatory security update once they clear the preview channel.