KB5124006: Cumulative update for Windows 11, version 26H1, September 2026. Remote Desktop failures reported; taskbar moves to four screen edges

• The Taskbar behaviors section is expanded by default, making its settings easier to find.¹
• The system tray loads more reliably on non-touch PCs.²

• The Start menu's Recommended section is renamed Recent.³
  The label also changes on Settings > Personalize > Start.
• The Start menu settings page is redesigned with separate controls for showing or hiding Pinned, Recommended, and All.⁴

• Search home is simplified, with less visual clutter and quicker access to recent searches.⁵
• Search results make it clearer whether an item is an app, setting, file, web result, or Store suggestion.⁶
• Windows automatically indexes your most-used folders so their files can appear in later searches. You can control this behavior in Settings.⁷
  The control is Settings > Privacy & Security > Search > Automatically find additional relevant locations.

• File Explorer Home launches faster and responds more quickly.⁸

• Progress indicators have a more consistent appearance during startup, sign-in, restart, shutdown, and update installation.⁹

• Switching between virtual desktops is smoother and more responsive.¹⁰

• Navigating to and interacting with Display settings is more reliable.¹¹
  Applies to Settings > System > Display.
• Previous brightness settings are more likely to remain in effect after Energy saver turns off.¹²

• App history information displays more reliably in Task Manager.¹³

• During Windows setup, it is easier to skip selecting a secondary keyboard when you do not need one.¹⁴
• The Get Started app adds App install, Site pinning, and Theme pages to help personalize the device and find features.¹⁵

• Recovery is more resilient to VPN background issues that could cause processes to stop responding.¹⁶
• The output of the wlanreport command is improved for Japanese users.¹⁷
  Applies to netsh wlan show wlanreport.

• Typing with the Japanese IME is more reliable, with fewer potential hangs.¹⁸
• Voice typing settings for automatic punctuation and the launcher are more likely to persist.¹⁹

For: users of supported languages and regions

• The Intelligent Carveout interface is more accessible and easier to use, with improved translations across supported languages and regions.²⁰

For: Copilot+ PCs

• Image Search, Content Extraction, Semantic Analysis, and Settings Model are updated to version 1.2607.840.0.²¹
  AI components apply only to Copilot+ PCs and do not install on other Windows client PCs or Windows Server.

• The included servicing stack update improves the reliability of Windows update installation.²²
  Includes KB5124005, build 28000.3081.

• You can place the taskbar at the bottom, top, left, or right of the screen. Search and the smaller taskbar option are supported only at the top and bottom.²³
  Change the position under Settings > Personalization > Taskbar > Taskbar behaviors > Taskbar position.
• A smaller taskbar option reduces the taskbar height and icon size while keeping Start, Search, and the system tray available.²⁴
  Set the size to Small under Settings > Personalization > Taskbar > Taskbar behaviors > Taskbar size.

• You can choose a small or large Start menu, in addition to the Automatic size.²⁵
  The setting is under Settings > Personalize > Start > Start menu size.
• You can hide your name and profile picture in Start.²⁶
  Use Settings > Personalize > Start > Hide your name and profile picture on Start.

• A new setting lets you choose whether web and Microsoft Store suggestions appear with local search results.²⁷
  The setting is under Settings > Privacy & Security > Search.

For: touch-screen devices

• You can scroll through the Recommended files carousel on File Explorer Home using touch.²⁸

For: work or school account users

• People signed in with a work or school account can discover and install relevant apps from the share window.²⁹
  Manage the option under Settings > System > Share > Show suggested apps in share surfaces.

• Administrator protection is beginning to roll out. It lets administrators perform tasks with temporary elevated privileges and is off by default.³⁰
  It can be enabled through OMA-URI in Microsoft Intune or through Group Policy. The feature is not classified as a formal security boundary.

For: users of participating apps

• Participating apps can coordinate updates with Windows Update for improved scheduling and a more streamlined update process.³¹
  This support is part of the Windows Update Orchestration Platform (UOP).

For: developers and users of supported apps

• Packaged WinUI 3 apps that require elevation can support in-app purchases through Microsoft's integrated commerce platform.³²

For: organizations using Windows Autopilot

• Device association is generally available to help organizations identify trusted devices before enrollment and apply device-targeted setup.³³
  It enables device-targeted policies, automatic corporate device enrollment, and additional out-of-box experience (OOBE) customization.

For: developers and organizations using execution containers

• Process Isolation adds a lightweight boundary that can restrict what workloads such as coding agents can access.³⁴
  Policy can restrict access to files, networking, the user interface, and other operating-system capabilities.

For: developers and organizations using agentic processes

• Windows adds preview support for marking agentic processes and passing that identifier to their child processes.³⁵
  When an agentic process authenticates through Web Account Manager (WAM), the identifier is included in the authentication request. The identifier format may change in future releases.

For: developers and IT administrators

• ML-KEM can now be used on its own for TLS key exchange, in addition to the previously added hybrid groups.³⁶

• A PC that was manually put to sleep returns to sleep after an update, even if automatic sleep is set to Never.³⁷

For: domain-joined devices configured to use Machine Identity Isolation in unsupported environments

• Affected domain-joined devices can keep their secure trust relationship with the domain, allowing users to sign in with valid domain credentials.³⁸
  Addresses Machine Identity Isolation issues in unsupported environments by disabling Machine Identity Isolation enforcement while improvements are made to the feature.

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

• File History can back up or restore files to an external drive or network location without incorrectly reporting that a working drive needs to be reconnected.³⁹