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



 Windows Insider Blog:

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.”


KB5122776 Enablement Package for 64-bit Windows 11 26H2​
Windows11.0-KB5122776-x64.msu (173 KB)​


OR​

KB5122776 Enablement Package for ARM64 Windows 11 26H2​
Windows11.0-KB5122776-arm64.msu (172 KB)​



KB5121794 Enablement Package for 64-bit Windows 11 26H2​
Windows11.0-KB5121794-x64.msu (174 KB)​


OR​

KB5121794 Enablement Package for ARM64 Windows 11 26H2​
Windows11.0-KB5121794-arm64.msu (174 KB)​


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.

www.elevenforum.com

Start Getting Insider Preview Builds on Windows 11 PC

This tutorial will show you how to get and install Insider preview builds of Windows 11 on your Windows 11 PC. Flighting is the process of running Windows Insider Preview Builds on your device. When you run these early versions of Windows and give Microsoft feedback, you can help Microsoft...
www.elevenforum.com www.elevenforum.com

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.

www.elevenforum.com

Download Official Windows 11 ISO file from Microsoft

This tutorial will show you how to download an official Windows Server or Windows 11 64-bit or ARM64 ISO file from Microsoft. Microsoft provides ISO files for Windows Server and Windows 11 to download. You can use these ISO files to clean install or in-place upgrade Windows 11. The Flight Hub...
www.elevenforum.com www.elevenforum.com

Thanks,
Windows Insider Program Team



 Source:

blogs.windows.com

Releasing Windows 11, version 26H2 to the Release Preview Channel

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 a
blogs.windows.com blogs.windows.com
learn.microsoft.com

Release Preview Build 26300.9278 - Windows Insider Program

Release notes for Release Preview Build 26300.9278.
learn.microsoft.com


Check Windows Updates


UUP Dump:

64-bit ISO download:
uupdump.net

Select language for Windows 11, version 26H2 (26300.9278) amd64

Select language for Windows 11, version 26H2 (26300.9278) amd64 on UUP dump. UUP dump lets you download Unified Update Platform files, like Windows Insider updates, directly from Windows Update.
uupdump.net

ARM64 ISO download:
uupdump.net

Select language for Windows 11, version 26H2 (26300.9278) arm64

Select language for Windows 11, version 26H2 (26300.9278) arm64 on UUP dump. UUP dump lets you download Unified Update Platform files, like Windows Insider updates, directly from Windows Update.
uupdump.net

www.elevenforum.com

UUP Dump - Download Windows Insider ISO

UUP Dump is the most practical and easy way to get ISO images of any Insider Windows 10 or Windows 11 version, as soon as Microsoft has released a new build. UUP Dump creates a download configuration file according to your choices, downloads necessary files directly from Microsoft servers, and...
www.elevenforum.com www.elevenforum.com
 

Attachments

Last edited:
Click to expand...
garlin said:
You can use MCT to download the ISO, but instead of allowing MCT to create an USB drive, you select save to ISO file.
Now use Rufus, and it's HW bypass option to write the same ISO file to the USB.

MCT is on a normal schedule where it drops the latest monthly ISO at the end of Patch Tuesday's week. Typically on this Thursday or Friday.
Click to expand...
What is MCT?
 

My Computer My Computer

At a glance

Wind 11 Pro 24H2 (Dev Channel)/23H2Beta (offl...2 Intel Xeon 5680120 GbMSI(Nvidia) GeForce GTX 970
OS
Wind 11 Pro 24H2 (Dev Channel)/23H2Beta (offline)
Computer type
PC/Desktop
Manufacturer/Model
DELL T7500
CPU
2 Intel Xeon 5680
Memory
120 Gb
Graphics Card(s)
MSI(Nvidia) GeForce GTX 970
Monitor(s) Displays
Dell S2719DGF
Screen Resolution
2560 x 1440 (155Hz)
Hard Drives
Samsung 2TB 870 (24H2 Device)
Samsung 1TB 860 (23H2 Beta)
PSU
Dell 1100W
Antivirus
Premium Malwarebyte, AdwCleaner (Malwarebyte)

My Computers My Computers

System One System Two

  • At a glance

    Windows 11 25H2Intel Core Ultra 9 275HX (24-Core)64GB DDR5 6400MT/sNVIDIA GeForce RTX 5080 and Intel UHD Graphics
    OS
    Windows 11 25H2
    Computer type
    Laptop
    Manufacturer/Model
    Alienware 18 Area-51
    CPU
    Intel Core Ultra 9 275HX (24-Core)
    Motherboard
    Alienware
    Memory
    64GB DDR5 6400MT/s
    Graphics Card(s)
    NVIDIA GeForce RTX 5080 and Intel UHD Graphics
    Sound Card
    Onboard, Realtek high-performance Audio chips (ALC3329 & ALC1708))
    Monitor(s) Displays
    300HZ 18-inch QHD 500 nit Comfort View+
    Screen Resolution
    2560 x 1600
    Hard Drives
    2TB NVMe M.2 PCIe Gen 5 SSD
    Case
    Magnesium Alloy
    Cooling
    Advanced Cryo-Tech Quad-Fan Cooling system & large vapor chamber
    Keyboard
    Cherry MX ultra low profile mechanical keyboard with per key AlienFX RGB lighting
    Mouse
    Logitech MX Master 4
    Browser
    Vivaldi (main), Firefox, Chrome, Edge
    Antivirus
    MS Defender and Malwarebytes Free

  • At a glance

    Windows 11 26H2Qualcomm Snapdragon X Elite (12 Core) ARM bas...16GB LPDDR5Qualcomm Adreno X1-85
    Operating System
    Windows 11 26H2
    Computer type
    Laptop
    Manufacturer/Model
    Microsoft Surface Laptop 7
    CPU
    Qualcomm Snapdragon X Elite (12 Core) ARM based CPU
    Motherboard
    Microsoft Corp.
    Memory
    16GB LPDDR5
    Graphics card(s)
    Qualcomm Adreno X1-85
    Sound Card
    Omnisonic speakers with Dolby Atmos spatial sound
    Monitor(s) Displays
    120 Hz 13.8-inch 600 nit PixelSense Flow touchscreen
    Screen Resolution
    2304x1536
    Hard Drives
    1TB NVMe Gen 4 SSD
    Case
    Anodized Aluminum
    Cooling
    Traditional active cooling fan system
    Keyboard
    Mechanical QWERTY, backlit when in use
    Mouse
    Logitech MX Master 4 and Surface Arc Mouse
    Browser
    Vivaldi (main), Firefox, Chrome, Edge
    Antivirus
    MS Defender and Malwarebytes Free
The direct download ISO is always out of date, it has always been intended for IT admins as a baseline ISO for applying their own updates. But many tech sites blindly suggest users install it.

Media Creation Tool (MCT) is the preferred download app for MS delivering a monthly updated ISO to end-users. For 25H2, it's refreshed every month since October 2025. The delay between Patch Tuesday and the latest MCT is down to about a week.

MCT is currently serving:
26200.9168.260809-0632.25h2_ge_release_svc_refresh

That's the August 2026 build. By Friday, it will be Sept 2026. If you don't believe that wait until @Brink posts that on Friday morning.
 

My Computer My Computer

At a glance

Windows 7
OS
Windows 7
garlin said:
The direct download ISO is always out of date, it has always been intended for IT admins as a baseline ISO for applying their own updates. But many tech sites blindly suggest users install it.

Media Creation Tool (MCT) is the preferred download app for MS delivering a monthly updated ISO to end-users. For 25H2, it's refreshed every month since October 2025. The delay between Patch Tuesday and the latest MCT is down to about a week.

MCT is currently serving:
26200.9168.260809-0632.25h2_ge_release_svc_refresh

That's the August 2026 build. By Friday, it will be Sept 2026. If you don't believe that wait until @Brink posts that on Friday morning.
Click to expand...
Thanks for the information!
 

My Computer My Computer

At a glance

Wind 11 Pro 24H2 (Dev Channel)/23H2Beta (offl...2 Intel Xeon 5680120 GbMSI(Nvidia) GeForce GTX 970
OS
Wind 11 Pro 24H2 (Dev Channel)/23H2Beta (offline)
Computer type
PC/Desktop
Manufacturer/Model
DELL T7500
CPU
2 Intel Xeon 5680
Memory
120 Gb
Graphics Card(s)
MSI(Nvidia) GeForce GTX 970
Monitor(s) Displays
Dell S2719DGF
Screen Resolution
2560 x 1440 (155Hz)
Hard Drives
Samsung 2TB 870 (24H2 Device)
Samsung 1TB 860 (23H2 Beta)
PSU
Dell 1100W
Antivirus
Premium Malwarebyte, AdwCleaner (Malwarebyte)
garlin said:
The direct download ISO is always out of date, it has always been intended for IT admins as a baseline ISO for applying their own updates. But many tech sites blindly suggest users install it.

Media Creation Tool (MCT) is the preferred download app for MS delivering a monthly updated ISO to end-users. For 25H2, it's refreshed every month since October 2025. The delay between Patch Tuesday and the latest MCT is down to about a week.

MCT is currently serving:
26200.9168.260809-0632.25h2_ge_release_svc_refresh

That's the August 2026 build. By Friday, it will be Sept 2026. If you don't believe that wait until @Brink posts that on Friday morning.
Click to expand...
Do you have a direct link to Microsoft ISO files?
 

My Computer My Computer

At a glance

Wind 11 Pro 24H2 (Dev Channel)/23H2Beta (offl...2 Intel Xeon 5680120 GbMSI(Nvidia) GeForce GTX 970
OS
Wind 11 Pro 24H2 (Dev Channel)/23H2Beta (offline)
Computer type
PC/Desktop
Manufacturer/Model
DELL T7500
CPU
2 Intel Xeon 5680
Memory
120 Gb
Graphics Card(s)
MSI(Nvidia) GeForce GTX 970
Monitor(s) Displays
Dell S2719DGF
Screen Resolution
2560 x 1440 (155Hz)
Hard Drives
Samsung 2TB 870 (24H2 Device)
Samsung 1TB 860 (23H2 Beta)
PSU
Dell 1100W
Antivirus
Premium Malwarebyte, AdwCleaner (Malwarebyte)

My Computer My Computer

At a glance

26200.8037i5-11400F32GBGeforce GT-1030
OS
26200.8037
Computer type
PC/Desktop
CPU
i5-11400F
Motherboard
Gigabyte
Memory
32GB
Graphics Card(s)
Geforce GT-1030
Keyboard
Logitech K400
Mouse
Logitech M720
Internet Speed
600 Mb
Browser
Edge
jimhow4545 said:
Do you have a direct link to Microsoft ISO files?
Click to expand...
The download page is always the same. The direct download ISO hasn't been refreshed since March 2026. It probably won't serve a newer ISO until 26H2 is officially released.

Download Windows 11
 

My Computer My Computer

At a glance

Windows 7
OS
Windows 7

My Computer My Computer

At a glance

Wind 11 Pro 24H2 (Dev Channel)/23H2Beta (offl...2 Intel Xeon 5680120 GbMSI(Nvidia) GeForce GTX 970
OS
Wind 11 Pro 24H2 (Dev Channel)/23H2Beta (offline)
Computer type
PC/Desktop
Manufacturer/Model
DELL T7500
CPU
2 Intel Xeon 5680
Memory
120 Gb
Graphics Card(s)
MSI(Nvidia) GeForce GTX 970
Monitor(s) Displays
Dell S2719DGF
Screen Resolution
2560 x 1440 (155Hz)
Hard Drives
Samsung 2TB 870 (24H2 Device)
Samsung 1TB 860 (23H2 Beta)
PSU
Dell 1100W
Antivirus
Premium Malwarebyte, AdwCleaner (Malwarebyte)
FrancoDT said:
Definitely not preferred if you have another choice. Microsoft didn't have an ISO for ARM to do a ISO repair install so a UUP Dump ISO was my only choice for ARM64.
Click to expand...
You can download the ARM builds, by analyzing MCT's products.cab file.

Run this PS script:
Code: 
powershell -ep bypass -f \folder\path\ProductsCAB2pastebin.ps1

The script will create a text file listing every image MCT knows about (including ARM versions). When you download the actual ESD file, it's not an ESD install image, but rather the entire ISO converted to an encrypted ESD file. Again if you wait until Friday, it should roll over to the Sept 2026 ISO's.

After downloading the ESD file, run abbodi1406's ESD decrypter to convert back to a normal ISO file.

BatUtil/esd-decrypter-wimlib at master · abbodi1406/BatUtil
https://raw.githubusercontent.com/a...ads/master/scripts/esd-decrypter-wimlib-66.7z

While this process isn't speedy, it beats UUP dump in total spent time.
 

Attachments

My Computer My Computer

At a glance

Windows 7
OS
Windows 7
garlin said:
You can download the ARM builds, by analyzing MCT's products.cab file.

Run this PS script:
Code: 
powershell -ep bypass -f \folder\path\ProductsCAB2pastebin.ps1

The script will create a text file listing every image MCT knows about (including ARM versions). When you download the actual ESD file, it's not an ESD install image, but rather the entire ISO converted to an encrypted ESD file.

After downloading the ESD file, run abbodi1406's ESD decrypter to convert back to a normal ISO file.

BatUtil/esd-decrypter-wimlib at master · abbodi1406/BatUtil
https://raw.githubusercontent.com/a...ads/master/scripts/esd-decrypter-wimlib-66.7z
Click to expand...
Ok. Thanks. Quick question. Is there a way to find the information ( what version of windows 11) of the ISO file ? I just downloaded the ISO files using MCT but it does not tell me the version.
 

My Computer My Computer

At a glance

Wind 11 Pro 24H2 (Dev Channel)/23H2Beta (offl...2 Intel Xeon 5680120 GbMSI(Nvidia) GeForce GTX 970
OS
Wind 11 Pro 24H2 (Dev Channel)/23H2Beta (offline)
Computer type
PC/Desktop
Manufacturer/Model
DELL T7500
CPU
2 Intel Xeon 5680
Memory
120 Gb
Graphics Card(s)
MSI(Nvidia) GeForce GTX 970
Monitor(s) Displays
Dell S2719DGF
Screen Resolution
2560 x 1440 (155Hz)
Hard Drives
Samsung 2TB 870 (24H2 Device)
Samsung 1TB 860 (23H2 Beta)
PSU
Dell 1100W
Antivirus
Premium Malwarebyte, AdwCleaner (Malwarebyte)
garlin said:
You can download the ARM builds, by analyzing MCT's products.cab file.

Run this PS script:
Code: 
powershell -ep bypass -f \folder\path\ProductsCAB2pastebin.ps1

The script will create a text file listing every image MCT knows about (including ARM versions). When you download the actual ESD file, it's not an ESD install image, but rather the entire ISO converted to an encrypted ESD file. Again if you wait until Friday, it should roll over to the Sept 2026 ISO's.

After downloading the ESD file, run abbodi1406's ESD decrypter to convert back to a normal ISO file.

BatUtil/esd-decrypter-wimlib at master · abbodi1406/BatUtil
https://raw.githubusercontent.com/a...ads/master/scripts/esd-decrypter-wimlib-66.7z

While this process isn't speedy, it beats UUP dump in total spent time.
Click to expand...
Thanks, hopefully I won't be doing any ISO installs in the near future as it's something I try to avoid until the recent DISM/Restorehealth errors became so hot and trendy with the recent Windows Updates.
 

My Computers My Computers

System One System Two

  • At a glance

    Windows 11 25H2Intel Core Ultra 9 275HX (24-Core)64GB DDR5 6400MT/sNVIDIA GeForce RTX 5080 and Intel UHD Graphics
    OS
    Windows 11 25H2
    Computer type
    Laptop
    Manufacturer/Model
    Alienware 18 Area-51
    CPU
    Intel Core Ultra 9 275HX (24-Core)
    Motherboard
    Alienware
    Memory
    64GB DDR5 6400MT/s
    Graphics Card(s)
    NVIDIA GeForce RTX 5080 and Intel UHD Graphics
    Sound Card
    Onboard, Realtek high-performance Audio chips (ALC3329 & ALC1708))
    Monitor(s) Displays
    300HZ 18-inch QHD 500 nit Comfort View+
    Screen Resolution
    2560 x 1600
    Hard Drives
    2TB NVMe M.2 PCIe Gen 5 SSD
    Case
    Magnesium Alloy
    Cooling
    Advanced Cryo-Tech Quad-Fan Cooling system & large vapor chamber
    Keyboard
    Cherry MX ultra low profile mechanical keyboard with per key AlienFX RGB lighting
    Mouse
    Logitech MX Master 4
    Browser
    Vivaldi (main), Firefox, Chrome, Edge
    Antivirus
    MS Defender and Malwarebytes Free

  • At a glance

    Windows 11 26H2Qualcomm Snapdragon X Elite (12 Core) ARM bas...16GB LPDDR5Qualcomm Adreno X1-85
    Operating System
    Windows 11 26H2
    Computer type
    Laptop
    Manufacturer/Model
    Microsoft Surface Laptop 7
    CPU
    Qualcomm Snapdragon X Elite (12 Core) ARM based CPU
    Motherboard
    Microsoft Corp.
    Memory
    16GB LPDDR5
    Graphics card(s)
    Qualcomm Adreno X1-85
    Sound Card
    Omnisonic speakers with Dolby Atmos spatial sound
    Monitor(s) Displays
    120 Hz 13.8-inch 600 nit PixelSense Flow touchscreen
    Screen Resolution
    2304x1536
    Hard Drives
    1TB NVMe Gen 4 SSD
    Case
    Anodized Aluminum
    Cooling
    Traditional active cooling fan system
    Keyboard
    Mechanical QWERTY, backlit when in use
    Mouse
    Logitech MX Master 4 and Surface Arc Mouse
    Browser
    Vivaldi (main), Firefox, Chrome, Edge
    Antivirus
    MS Defender and Malwarebytes Free

My Computer My Computer

At a glance

Windows 7
OS
Windows 7
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