Unlike older versions of Windows, Microsoft makes it rather easy to downloadWindows 11 installation media,if you know where to look. However, both the Media Creation Tool and the ISO files offered by Microsoft to regular users usually contain outdated builds, which means you have to download thelatest monthly updates during/after the installation phase. In case you need to service more than one PC, this design only exacerbates the problem.

Plus, Microsoft doesn't let you download official ISO files forWindows on Arm devices without a valid Volume License Service Center (VLSC) subscription. Furthermore, the company doesn't provide ISO files for every build released in theWindows Insider Program, hence performing a fresh installation for those builds isn't possible without being online and going through multiple hoops. Luckily, a community-led initiative provides the means to send manual queries to the Windows Update framework, known as the Unified Update Platform (UUP), and build a ready-to-use ISO image for every architecture and build out there. It's called UUP dump, and it's very useful.

What is UUP?

TheUnified Update Platform (UUP) is the latest generation of Microsoft's update delivery method, catering to all devices that run modern Windows-based OSes — regular PCs, tablets, convertibles, servers, IoT devices, and more — from a single update platform. The solution is absolutely modular in nature and it covers everything from monthly quality updates to annual feature updates to Windows Insider Preview builds.

The beauty of UUP lies in limiting the size of individual downloads. Instead of downloading the same monolithic update package to every device, it downloads only the necessary set of files for the target system for which updates are available. For a full Windows build, you aren't required to download a full-fledged ISO file or an encrypted ESD package, because UUP handles it by generating a list of highly compressed payloads based on the principle of differential upgrades, and then executing the relevant staging operations after a successful download, followed by the commits.

What is UUP dump and how does it work?

Microsoft has publicly started to use UUP sinceWindows 10 Insider Build 14986, released back in December 2016. A few months later, some developers over at theMy Digital Life forums came up with the UUP dump project after successfully reverse-engineering the protocol and the associated download mechanism. Initially started as a self-hosted PHP solution, it was later converted to a website, through which anyone can create a download configuration file according to their choices. You can then download the necessary files directly from Microsoft servers, and finally create an ISO image.

UUP dump is partially open-source. To avoid the rise of malicious copycats, the maintainers retain the strict need-to-know policy before handing over access to the core codebase. Nonetheless, there exist several forks of the project. The original website is currently not functional, so we'll be using a trusted mirror for this tutorial.

How to use UUP dump to create an ISO of any Windows build?

The UUP dump project allows users to create ISO files for Windows 11 (Canary, Dev, Beta, and Release Preview Insider channels, as well as production releases such as 22H2/22621.x and 21H2/22000.x), Windows 10 (22H2/19045.x, 21H2/19044.x, and 1809/17763.x) and Windows Server (22H2/20349.x and 21H2/20348.x). If you want to create Arm64 Windows ISOs for testing, you can do that as well. The cherry on top is that it can build multi-edition Windows images for consumer SKUs, and even output slipstreamed up-to-date ISOs, depending on the host OS.

You don't have to join the Windows Insider Program in order to create and install an Insider build of Windows using UUP dump. It is possible to make the query to the Windows Update server and simply download any build — be it a stable channel one or an Insider release — through the project. You can then either upgrade your current installation using the ISO, or perform a clean installation from scratch.

For Windows as the host OS

Due to the fact that servicing a Windows image requires tools and APIs only available in a compatible Windows OS instance, it's best to run the UUP dump script on a modern Windows OS, such as Windows 11 or 10. The following steps will show you how to use UUP dump to get a fully standalone Windows ISO.

1. Open your favorite browser and navigate to the following link to go to the UUP dump project:Mirror (original website no longer functions)
2. Under theQuick options card, select your preferred channel (Release type), and click the button for preferred CPU architecture.
   • If you're after a specific build, you can also the search function to locate it.

3. Click the link to your chosen build.
4. Select your desired language from the drop-down list (which is going to be the language of the ISO), and click onNext.
5. Choose the editions to be included and click onNext.
   • When it comes to servicing, Windows Home and Windows Pro are the base editions. All other editions are "virtual", which means you can up/downgrade to them on the fly from an existing Home/Pro installation with the appropriate key.
   • Windows Team is a specialized edition meant for the Surface Hub, hence it's hidden by default.
   • The "N" editions are regular Windows editions, minus the media components like Windows Media Player, Skype, or certain preinstalled media apps (Music, Video, Voice Recorder). You can't activate them with standard Windows product keys, as such SKUs need a specific N edition product key.

6. At this stage, you should be able to see a summary of your choices.
   • The default setting isDownload and convert to ISO. This is enough to create the installation media with only Home and Pro editions. Make sure that theInclude updates option is checked, otherwise you will not get a fully updated image. The remaining conversion options are for advanced users, so only tinker with them if you know what you're doing.
   • In case you want to include a handful of additional editions in your ISO, choose theDownload, add additional editions and convert to ISO option.

7. After reviewing everything, click on theCreate download package button. A ZIP archive file will be downloaded.
8. Use any file archiver to extract the contents of the ZIP file to a folder with a short file name.
9. Locate the file nameduup_download_windows.cmd and run it to start the download process.
   • The UUP download portion is handled byaria2. In some rare cases, the script is unable to download the aria2 binary and quits abnormally. In that case, make sure that your ISP is not blocking thegithub.com domain.

10. As soon as the download has finished, the script starts to convert the UUP payloads and build the ISO. The background color switching from black to blue is a crude-but-handy hint to detect the phase change.
    • For diagnosing any download-related errors, take a look at thearia2_download.log file. You can re-run the script to retry downloading the failed modules.

11. The ISO creation process will take some time. When everything's done, you will see a "Press 0 to exit" message. Do so, or just close the Command Prompt window manually.
12. The freshly baked ISO file can be found in the same folder where you extracted the ZIP archive.

For Linux/macOS as the host OS

While it is possible to download the raw UUP payloads under Linux or macOS, those non-Windows operating systems lack the libraries and executables required to handle them. As a result, the UUP dump configuration ZIP archive (refer to the previous section) comes with two separate scripts for downloading the UUP packages from macOS (uup_download_macos.sh) and Linux (uup_download_linux.sh), but there's no built-in conversion support.

However, you can use the UUP Media Creator to convert the UUP set into a proper ISO. UUP Media Creator actually contains a download tool as well, but it's not quite as straightforward as UUPdump. You can download it below.

Download UUP Media Creator

That’s all there is to it! After the ISO creation completes, you can install the build in a virtual machine, mount it, burn it, or create a bootable USB drive installer, all without having to learn complex Windows servicing commands. For the Insider builds, you can even evaluate them without enrolling in the Windows Insider Program. Doing a fresh installation with your desired Windows version has never been easier.