Insider Windows 11 Insider Release Preview build 26300.9278 (26H2) - Aug. 27

Hello Windows Insiders!

Today, we are making this year’s annual feature update, Windows 11, version 26H2 (Build 26300.9278), available in the Release Preview Channel for customers to preview ahead of general availability later this calendar year.

Windows 11, version 26H2 will be delivered as an enablement package (eKB). This means that Windows 11, versions 24H2, 25H2, and 26H2 use a shared servicing branch. It also means that they share the same new features and enhancements delivered through our continuous innovation efforts. As a result, many of the features and improvements available in Windows 11, version 26H2 might already be familiar, as they have been gradually introduced through monthly updates.

To use the correct enablement package based on your currently installed build:

KB5122776 is the enablement package for the Insider Experimental Preview Build 26340. In the installed updates list, it shows up as “Feature Enablement for Windows (Ge) 26H2 Insider Refresh - KB5122776 - 2026.08 A - BuildNumber Update.”

KB5121794 is the enablement package for the retail 26H2 release, listed as “Feature Enablement for Windows (Ge) 26H2 - KB5121794 - 2026.07 D.”

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For commercial customers, Windows 11, version 26H2 enables several experiences that were introduced in earlier releases but not previously enabled by default for commercial devices. This includes Windows settings backup, app-specific actions from the taskbar, and some File Explorer enhancements. For guidance on how to prepare for Windows 11, version 26H2 in your organization, see Get ready for Windows 11, version 26H2.

Windows Insiders in the Release Preview Channel can install Windows 11, version 26H2 via our “seeker” experience in Windows Update. This means if you are an Insider currently in the Release Preview Channel on a PC that meets the Windows 11 hardware requirements, you can go to Settings and Windows Update and choose to download and install Windows 11, version 26H2. Once you update your PC to Windows 11, version 26H2, you will continue to automatically receive new servicing updates through Windows Update (the typical monthly update process). For instructions on how to join the Windows Insider Program and enroll your PC in the Release Preview Channel, click here.


If you are a commercial customer enrolled in the Windows Insider Program for Business, you can deploy and begin validating Windows 11, version 26H2 on PCs in your organization using Windows Update client policies and Windows Server Update Services (WSUS). Azure Marketplace will be available later today. Should any issues arise, IT admins in organizations deploying Release Preview updates can request Microsoft Support.

And finally, ISOs are available for download for Windows 11, version 26H2 via the Windows Insider ISO download page.


Thanks,
Windows Insider Program Team






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