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Windows 11 24H2 / 25H2 / 26H2 Windows 11 24H2 / 25H2 / 26H2 Optional preview
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KB5124010

KB5124010: Cumulative update for Windows 11, versions 24H2, 25H2 and 26H2, September 2026. New touchpad gestures, emoji and Widgets; Remote Desktop issue remains

In short

Adds Windows features and fixes several problems, but non-admin Remote Desktop connections might still fail on managed devices with Administrator protection enabled. It is the final preview for version 24H2.

Does it affect you? Applies to: Devices running Windows 11, versions 26H2 (build 26300.9550), 25H2 (build 26200.9550), or 24H2 (build 26100.9550). The final-preview and end-of-support announcements apply to version 24H2.

Builds
26100.9550 · 26200.9550 · 26300.9550
Restart
Required

What changes

Improvements 24 changes

File Explorer

Gradual rollout
  • Cloud-file thumbnail previews in the Details pane are more reliable, and the pane's file properties are reorganized.1

Emoji

Gradual rollout
  • Several existing emoji designs are refined, including saluting face, face with peeking eye, goose, lotus, and kissing cat.2

Personalization

Gradual rollout Verified in package 5 items
  • The Background page in Settings is more reliable.3
    Settings > Personalization > Background
  • Desktop slideshow transitions are more reliable on newly created accounts.4
  • Background previews have higher resolution when selecting a desktop background.5
    Settings > Personalization > Background
  • Desktop background previews in Settings display better on portrait-mode monitors.6
  • Wallpaper changes made in quick succession are processed more reliably.7

Bluetooth

Gradual rollout Verified in package 6 items
  • During voice calls, the volume flyout shows the new level when you adjust a Bluetooth Classic Audio accessory's volume controls.8
  • Windows shows a more accurate connection state for accessories that have disconnected from the PC.9
  • The Bluetooth and devices page in Settings is more stable when managing Bluetooth and audio devices.10
  • Microphone compatibility improves with certain Bluetooth Classic audio accessories.11
  • Bluetooth audio is more reliable and performs better with LE Audio accessories.12
  • Shared audio is more reliable.13

Accessibility

Gradual rollout Verified in package

For: Users navigating with keyboard input, gamepad input, or Narrator

  • The Bluetooth quick settings page is easier to navigate with a keyboard, gamepad, or Narrator.14

Magnifier

Gradual rollout Verified in package

For: Users of Magnifier

  • The Magnifier taskbar has updated icons and adjusted spacing and padding.15

Settings

Gradual rollout Verified in package 3 items
  • Settings is more reliable when you use the Printers & Scanners page.16
    Settings > Bluetooth & Devices > Printers & Scanners
  • Installed apps shows the version number at the top level for packaged apps.17
    Settings > Apps > Installed apps
  • The time picker reflects your preferred 12-hour or 24-hour time format, including when setting active hours or scheduling Night light.18

Fonts

Gradual rollout

For: Users of Adlam

  • Adlam glyph designs in Ebrima are refined to align with the current Unicode standard and improve consistency.19

Kiosk mode

Gradual rollout 2 items
  • The Windows + Tab shortcut is disabled in restricted UX kiosk mode.20
  • The Windows + A and Windows + C shortcuts are disabled in single-app kiosk mode.21

Power and battery

Gradual rollout

For: Some plugged-in laptops

  • Display and performance improve in some cases where a plugged-in laptop incorrectly detects a switch from AC power to battery.22

AI components

Verified in package

For: Copilot+ PCs

  • Image Search, Content Extraction, Semantic Analysis, and Settings Model are updated.23
    The AI components are updated to version 1.2608.951.0 and apply only to Copilot+ PCs; they do not install on other Windows client PCs or Windows Server.

Servicing stack

Verified in package
  • The included servicing stack update improves the reliability of Windows update installation.24
    Includes KB5124009, build 26100.9539.

New features 14 changes

File Explorer

Gradual rollout 2 items
  • For downloaded HTML files, the preview pane offers a Preview anyway button after the warning. Other files, such as PDFs, preview automatically.25
  • File Explorer Home remembers whether its sections were expanded or collapsed.26

Emoji

Gradual rollout
  • The emoji panel adds Emoji 17.0 characters, including distorted face, fight cloud, and hairy creature.27
    Open the emoji panel with Windows + .

Widgets

Gradual rollout Verified in package
  • The Tips widget provides short guidance about Windows features and can be added to the Widgets board or lock screen.28
    Add it from the Widgets board's Add widgets option or in Settings > Personalization > Lock screen.

Personalization

Gradual rollout 2 items
  • DIB image files can be used as desktop backgrounds.29
  • Slideshow wallpapers can be used with multiple desktops without automatically switching back to Picture.30

Accessibility

Gradual rollout Verified in package
  • The Open apps maximized setting automatically maximizes app windows as they open.31
    Turn it on in Settings > Accessibility > Visual effects.

Touchpad

Gradual rollout Verified in package 2 items
  • Precision touchpads support vertical scrolling with one finger starting from the left or right side.32
    Settings > Bluetooth & devices > Touchpad
  • Precision touchpads support automatic scrolling when you move your fingers near the edge while scrolling.33
    Settings > Bluetooth & devices > Touchpad

Copilot key

Gradual rollout

For: Devices with a Copilot key

  • A new setting lets you remap the Copilot key to Right Ctrl or Context Menu.34

Camera roll

Gradual rollout Verified in package
  • Camera roll backup in Settings lets eligible users protect photos with OneDrive and complete setup on a mobile phone using a QR code.35
    The feature can be enabled from Settings Home or Accounts. Availability depends on the device and market.

Fonts

Gradual rollout

For: Users of the supported scripts

  • The Ebrima font adds support for the Garay and Beria Erfe scripts.36
    Garay is encoded in Unicode 16.0 and Beria Erfe in Unicode 17.0.

Windows Recovery (WinRE)

For: IT administrators using MDM providers

  • A recovery remote management plug-in extends WinRE management capabilities for MDM providers.37

Date and Time

For: Devices using time zones in British Columbia or Alberta

  • Permanent Daylight Saving Time support is added for British Columbia and Alberta starting in November 2026.38

Fixes 10 changes

File Explorer

Gradual rollout
  • Clicking near the right side of the address bar to edit it no longer causes its contents to be cleared.39

Bluetooth

Gradual rollout Verified in package 2 items
  • The Bluetooth radio control no longer shows as on when the radio is turned off.40
    Bluetooth and devices page in Settings
  • Streaming Bluetooth audio no longer causes a crash with error code 0x139.41

Settings

Gradual rollout Verified in package
  • The option allowing multiple apps to use the camera at the same time is retained more reliably.42
    Settings > Bluetooth & Devices > Camera settings

Secure Trust

  • Domain-joined devices configured to use Machine Identity Isolation in unsupported environments are less likely to lose their secure trust relationship, which could prevent sign-in with valid domain credentials.43
    The issue affected Machine Identity Isolation configurations in environments where the feature is unsupported.

Camera

  • The built-in camera is less likely to stop working in the Camera app or other apps that use it.44

File History

For: Devices using File History with an external drive or network location

  • File History is less likely to fail when backing up or restoring files to an external drive or network location, or to incorrectly report that you need to reconnect a working drive.45

System Monitor (Sysmon)

Verified in package 3 items
  • Malformed or truncated executable files no longer cause unpredictable memory use that can make tampering detection unreliable.46
    Fixes executable-file header validation.
  • A stop error no longer occurs when the Sysmon file system filter driver closes an uninitialized handle after the archive directory fails to open during monitoring.47
  • Sysmon no longer incorrectly reports Event ID 25 alerts for the Windows Session Manager process.48
    The affected process is smss.exe.

Removal 1 change

Windows Backup

Gradual rollout Verified in package

For: People moving to a new PC

  • PC-to-PC Migration is no longer available. Microsoft recommends Windows Backup to transfer and restore supported files, settings, and other items.49

Known issues

  1. Resolved Affects: Organizations and IT administrators

    Remote Desktop connections might fail for non-admin users with error 0xC000000D

    Non-admin users might be unable to connect by Remote Desktop to remote host devices with Administrator protection enabled. Connections can fail with error 0xC000000D and the message “The token that was passed to the function is invalid.” The issue primarily affects enterprise-managed hosts.50

    How to apply the workaround Group Policy / Intune

    Temporarily turn off Administrator protection by resetting the User Account Control Type Of Admin Approval Mode policy in Intune or Group Policy.50

    Step-by-step workaround instructions
    2 steps
    Show steps Hide steps
    Step-by-step procedure
    1. Use your existing policy management method in Microsoft Intune or Group Policy.
    2. Reset the User Account Control Type Of Admin Approval Mode policy on affected devices.
  2. Resolved Affects: Everyone Resolved by KB5132059

    USB audio devices might fail to start or produce no sound

    Some USB Audio Class 1.0 devices might fail to start or produce audio. Symptoms can include Device Manager error Code 10, no output, unresponsive volume controls, or unavailable sound settings.51

    Resolution Fixed in KB5132059

    Install KB5132059 (or a later cumulative update) on affected devices. No manual workaround is required after updating.

  3. Resolved Affects: Everyone Resolved by KB5127648

    Applications which require AC-3 audio decoding might close unexpectedly

    Some applications that rely on Windows built-in AC-3 (Dolby Digital) audio decoding might fail to launch or close unexpectedly when certain audio features are used. KB5127648 and later updates resolve this issue.52

    Resolution Fixed in KB5127648

    Install KB5127648 (or a later cumulative update) on affected devices. No manual workaround is required after updating.

  4. Resolved Affects: Organizations and IT administrators Resolved by KB5127648

    Devices might experience a black screen or desktop loading issues after sign-in

    Some devices, primarily Azure Virtual Desktop hosts using FSLogix, might show a black screen after sign-in or fail to load the desktop automatically. KB5127648 and later updates resolve this issue.53

    Resolution Fixed in KB5127648

    Install KB5127648 (or a later cumulative update) on affected devices. No manual workaround is required after updating.

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released
2026-09-22
Classification
Updates
Type
Cumulative update
Restart
Required
Replaces
KB5129195, KB5124008, KB5120998, KB5121003
+61 earlier KB5101684, KB5121767, KB5101650, KB5095093, KB5094126, KB5089573, KB5089549, KB5083631, KB5083769, KB5086672, KB5079391, KB5085516, KB5079473, KB5077241, KB5077181, KB5074105, KB5078127, KB5077744, KB5074109, KB5072033, KB5070311, KB5068861, KB5067036, KB5070773, KB5066835, KB5065789, KB5068221, KB5065426, KB5064081, KB5063878, KB5062660, KB5064489, KB5062553, KB5060829, KB5063060, KB5060842, KB5058499, KB5061977, KB5058411, KB5055627, KB5059087, KB5055523, KB5053656, KB5053598, KB5052093, KB5051987, KB5050094, KB5050009, KB5048667, KB5046740, KB5046617, KB5044384, KB5044284, KB5043178, KB5043080, KB5041865, KB5041571, KB5040529, KB5040435, KB5039304, KB5039239
Replaced by
KB5127648
VersionBuildChannel
24H2 26100.9550 General availability
24H2 26100.9539 Release Preview Channel
25H2 26200.9550 General availability
25H2 26200.9539 Release Preview Channel
26H2 26300.9550 General availability
26H2 26300.9539 Release Preview Channel
26H2 26300.9550 Release Preview Channel

Security

No vulnerabilities are listed for this update.

Updated components

11,724 files changed since the previous update for the same versions.

Top changed componentsFiles
Settings158
Bluetooth68
Graphics and display67
Networking55
Printing54
Audio51
Remote Desktop48
Security and sign-in47
.NET networking40
Hyper-V and virtualization36
File Explorer and shell35
Windows Update30

Verified in package: changed files confirm Personalization, Bluetooth, Accessibility, Magnifier, Settings, AI components, Servicing stack, Widgets, Touchpad, Camera roll, System Monitor (Sysmon), Windows Backup.

Page history

  1. Known issue resolved: USB Audio Class 1.0 devices with error Code 10 or no output (KB5132061)

  2. Known issue resolved: Remote Desktop connections might fail for non-admin users with error 0xC000000D

  3. Now also covers build 26300.9539 (26H2, Release Preview Channel)

Sources

Updated
Cited passages from Microsoft's official notes (53)
  1. 1. This update improves the reliability of thumbnail previews for cloud files in the Details pane. support.microsoft.com
  2. 2. This update also refines the design of several existing emoji for better consistency across platforms, including saluting face, face with peeking eye, goose, lotus, and kissing cat. support.microsoft.com
  3. 3. This update improves the reliability of the Personalization > Background page in Settings. support.microsoft.com
  4. 4. This update improves reliability of desktop slideshow transitions on newly created accounts. support.microsoft.com
  5. 5. This update improves resolution of previews when selecting a desktop background in Personalization > Background. support.microsoft.com
  6. 6. This update improves desktop background preview display in Settings for users with portrait mode monitors. support.microsoft.com
  7. 7. This update improves reliability of processing desktop wallpaper changes when they happen in quick succession. support.microsoft.com
  8. 8. During voice calls, the Windows shell volume flyout now appears when adjusting the volume of a Bluetooth Classic Audio accessory via the volume controls on the accessory support.microsoft.com
  9. 9. This update improves the accuracy of the connection state displayed by Windows for accessories that have disconnected from the PC. support.microsoft.com
  10. 10. This update improves stability of the Bluetooth and devices page in Settings when managing Bluetooth and audio devices. support.microsoft.com
  11. 11. This update improves microphone compatibility with certain Bluetooth Classic audio accessories. support.microsoft.com
  12. 12. This update improves reliability and performance with LE Audio accessories. support.microsoft.com
  13. 13. This update improves the reliability of shared audio. support.microsoft.com
  14. 14. This update improves navigation of the Bluetooth quick settings page when using keyboard input, gamepad input, or Narrator. support.microsoft.com
  15. 15. This update brings a modernized visual refresh to the Magnifier taskbar. support.microsoft.com
  16. 16. This update improves the reliability of Settings when interacting with the contents of the Settings > Bluetooth & Devices > Printers & Scanners page. support.microsoft.com
  17. 17. This update updates Settings > Apps > Installed apps to show the version number at the top level for packaged apps support.microsoft.com
  18. 18. This update improves the time picker control in Settings so that it reflects your preferred time format when you switch between 12-hour and 24-hour time. support.microsoft.com
  19. 19. This update also refines the Adlam glyph designs in Ebrima to align with the current Unicode standard and improve consistency. support.microsoft.com
  20. 20. The Windows + Tab keyboard shortcut is now disabled when using a restricted UX kiosk. support.microsoft.com
  21. 21. The Windows + A and Windows + C keyboard shortcuts are now disabled when using single-app kiosk mode. support.microsoft.com
  22. 22. This update improves display and performance in certain scenarios where a plugged-in laptop incorrectly detects a transition from AC power to battery power. support.microsoft.com
  23. 23. This release updates the following AI components to version 1.2608.951.0: Image Search, Content Extraction, Semantic Analysis, and Settings Model. support.microsoft.com
  24. 24. Includes KB5124009 (Build 26100.9539), which improves the reliability of the Windows update installation process. support.microsoft.com
  25. 25. For HTML files, a new Preview anyway button lets you acknowledge the warning and preview the file. Non-HTML files, such as PDFs, are now previewed automatically. support.microsoft.com
  26. 26. File Explorer Home now preserves the state of sections (expanded or collapsed), so you can pick up where you left off. support.microsoft.com
  27. 27. This update adds support for Emoji 17.0, including new emoji such as distorted face, fight cloud, and hairy creature. support.microsoft.com
  28. 28. This update introduces the Tips widget, which provides short, helpful guidance about Windows features. support.microsoft.com
  29. 29. This update adds support for using DIB image files as desktop backgrounds. support.microsoft.com
  30. 30. This update adds support for using slideshow wallpapers with multiple desktops, so that it won’t automatically switch you back to Picture. support.microsoft.com
  31. 31. This update introduces Open apps maximized, an accessibility setting that automatically maximizes app windows as they open. support.microsoft.com
  32. 32. Single-finger scrolling — Scroll vertically with one finger starting from the left or right side of the touchpad. support.microsoft.com
  33. 33. Automatic scrolling — Keep scrolling without lifting your fingers by moving them near the edge of your touchpad while scrolling. support.microsoft.com
  34. 34. This update introduces a new Windows 11 setting that lets you remap the Copilot key to function as the Right Ctrl or Context Menu key support.microsoft.com
  35. 35. This update introduces Camera roll backup in Settings, helping eligible users protect their photos with OneDrive. support.microsoft.com
  36. 36. This update adds support for the Garay and Beria Erfe scripts to the Ebrima font support.microsoft.com
  37. 37. This update adds a recovery remote management plug-in for extending WinRE management capabilities for MDM providers. support.microsoft.com
  38. 38. This update adds support for permanent Daylight Saving Time (DST) in British Columbia and Alberta beginning in November 2026. support.microsoft.com
  39. 39. The update addresses an issue that could clear the address bar contents when entering edit mode by clicking near the right side of the address bar. support.microsoft.com
  40. 40. This update resolves an issue where the Bluetooth radio could be turned off, but the state of the radio control toggle in the Bluetooth and devices page in Settings shows as on. support.microsoft.com
  41. 41. This update resolves an issue that could result in a crash (error code 0x139) while streaming Bluetooth audio. support.microsoft.com
  42. 42. This update improves persistence of the Allow multiple apps to use camera at the same time option in Settings > Bluetooth & Devices > Camera settings. support.microsoft.com
  43. 43. This update fixes an issue that could cause domain-joined devices to lose their secure trust relationship with an Active Directory domain. support.microsoft.com
  44. 44. This update addresses an issue where the built-in camera might stop working in the Camera app and other apps that use the camera. support.microsoft.com
  45. 45. This update addresses an issue where File History might fail to back up or restore files to an external drive or network location. support.microsoft.com
  46. 46. Truncated or malformed files could cause unpredictable memory use and result in unreliable tampering detection. support.microsoft.com
  47. 47. If the archive directory failed to open during file monitoring, closing an uninitialized handle could cause a stop error. support.microsoft.com
  48. 48. Sysmon incorrectly generated Event ID 25 alerts for the Windows Session Manager (smss.exe) process. support.microsoft.com
  49. 49. To back up and restore your files, settings, and other supported items when moving to a new PC, use Windows Backup. support.microsoft.com
  50. 50. Reset the User Account Control Type Of Admin Approval Mode policy in Microsoft Intune or Group Policy. support.microsoft.com
  51. 51. After installing the September 8, 2026, Windows security update, some USB Audio Class 1.0 devices might fail to start or produce audio. support.microsoft.com
  52. 52. This issue is resolved in Windows updates released on and after October 13, 2026 such as KB5127648. support.microsoft.com
  53. 53. This issue was resolved by Windows updates released October 13, 2026 (KB5127648), and updates released after that date. learn.microsoft.com
Checked automatically: 8 of 8 checks passed, 53 quoted passages · compared with Microsoft's page on Nov 14, 2026
  • Quotes found in the official pages: passed
  • Numbers found in the sources: passed
  • Vulnerabilities from the dossier only: passed
  • Links to allowed domains only: passed
  • Every official change covered: passed
  • Readable plain text: passed
  • Changes confirmed by the file list: passed
  • Sources agree: passed

A second AI read the text against the sources: correctness 4/5, clarity 4/5, completeness 4/5. How we work

Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake