How to download Windows 11 25H2 ISO file (preview)

• You can download the Windows 11 25H2 ISO file using the UUP Dump tool, which generates an ISO for build 26200.5670 or newer.
• After downloading, use Rufus to create a bootable USB drive for a clean installation or upgrade, even on unsupported hardware.

Although Windows 11 25H2 won’t be officially available until sometime in the fall of 2025, you can download the latest Insider preview ISO file using the “UUP Dump” tool to perform a clean install or an in-place upgrade on a spare computer or virtual machine to start testing the upcoming new features and changes.

“UUP Dump” is a popular tool that allows you to create a custom Windows 11 ISO file from any public preview. The tool is a collection of scripts that connect to and download the latest builds from the official Microsoft servers, creating an unofficial ISO file to install the operating system. You can also use the “Windows Insider Preview Downloads” website, but previews on the page are only available when Microsoft publishes them (and currently that’s not the case).

Since the Windows 11 2025 Update is still under development, please note that features, changes, and fixes may not function as expected, and you may encounter issues, including data loss. It’s recommended to create a backup of your computer before installing this version. You have been warned.

In this guide, I will teach you how to download the ISO file for any publicly available preview of Windows 11 (version 25H2) and create a bootable USB media with the Rufus tool.

• Download Windows 11 25H2 ISO file from UUP Dump
• Create Windows 11 25H2 bootable USB using Rufus

Download Windows 11 25H2 ISO file from UUP Dump

To download the Windows 11 ISO file with the UUP Dump tool, use these steps:

1. Open the UUP Dump page.

2. Click the Downloads tab.

3. Select the “Windows 11 Insider Preview” option to download the latest (x64) ISO file, for example, build 26200.5670.

   

   Quick tip: In the case of version 25H2, always choose a build equal to or higher than 26200.5670. If you have a Copilot+ PC or a device using an ARM processor, then download the “arm64” architecture.

4. Select the language for the installation in the “Language” setting.

   

5. Click the Next button.

6. Select the version 25H2 editions to include in the Windows 11 ISO file.

   

7. Click the Next button.

8. Select the “Download and convert to ISO” option.

   

9. Check the “Include updates (Windows converter only)” option.

   Quick note: This step enables the script to integrate the updates, resulting in an ISO file version 25H2.

10. Click the “Create download package” button to save the tool on your computer.

11. Open the zip folder with File Explorer.

12. Click the Extract all button.

    

13. Select the location where you want to extract the files.

14. Click the Extract button.

15. Right-click the “uup_download_windows.cmd” batch file and select the Run as administrator option.

    

16. Click the More info option.

17. Click the “Run anyway” button to begin the lengthy process.

18. Press the “R” key to run the script once, and then press Enter.

19. Press the 0 key when prompted to close the screen.

Once you complete the steps, the Windows 11 25H2 ISO file will be created inside the folder where you extracted the UUP Dump tool. This process can take up to an hour or more, depending on your internet connection and the work that it takes for the script to run.

If you encountered an issue while running the UUP Dump script, within the script folder, right-click the “Remove_Failure_MountDr_TempDir.cmd” and choose the “Run as administrator” option. After the process completes, run UUP Dump one more time.

Also, ensure that your computer has sufficient space to allow the script to process the files to avoid issues and delays. Typically, the device requires approximately 70GB of free space on the primary drive.

Create a Windows 11 bootable USB using Rufus

To create a bootable USB with Rufus to install Windows 11 25H2, use these steps:

1. Open the Rufus website.

2. Click the link to download the latest version under the “Download” section.

3. Double-click the rufus.x.xx.exe file to launch the tool.

4. Select the USB flash drive from the drop-down menu under the “Device” section to create Windows 11 bootable media.

5. Click the Select button.

   

6. Select the Windows 11 25H2 ISO file.

7. Click the Open button.

8. Select the “Standard Windows 11 Installation” option under the “Image option” setting.

9. Select the GPT option under the “Partition scheme” section.

10. Choose the UEFI (non-CSM) option under the “Target system” section.

11. Specify a descriptive name for the bootable USB drive in the “Volume label” section—for example, “Windows 11 25H2 Setup”.

12. Use the default settings for the File system and Cluster size options.

13. Check the Quick format option.

14. Check the “Create extended label and icon files” option.

15. Clear all the checked options if the computer is compatible with Windows 11. 

    

    Quick note: Check the “Remove requirement for 4GB+ RAM, Secure Boot and TPM 2.0” and “Remove requirement for an online Microsoft account” options to create a USB media for unsupported hardware.

16. Click the Start button.

17. Click the OK button to confirm the deletion of the USB drive and the creation of the bootable drive.

After you complete the steps, the tool will create a USB bootable media with the Windows 11 25H2 installation files.

Alternatively, you can use other tools like Ventoy, which allows you to create a bootable media by sampling and dropping multiple ISO files on the USB flash drive. You can even create a bootable media with the Command Prompt.