UUP Dump web site allows to download latest Windows 10 builds using Microsoft Unified Update Platform.
Tips: you can see all Windows 10 releases from Windows 10 Update History page of Microsoft web site.
Once you have picked the desired build you have to choose the language and next the editions you want to download (eg. Home, Pro or all).
Finally you can browse the list of files for manual download or download the selected UUP set using Aria2, or download the selected UUP set using aria2 and convert it to ISO, or download the selected UUP set using aria2, create virtual editions and convert it to ISO.
Tips: you can see your actual Windows version / build installed by typing “winver” from command prompt or go to Settings -> System -> About.
UUPDL + UUP Converter Guide
UUPDL is a tool that can allows you to do same tasks easily from command line interface.
Once you have decompressed the archive open the uup.downloader.cmd file, you can choose between the following options:
[R] RELEASE DOWNLOAD QUERY
[C] CHECK FOR NEW RELEASES
[S] SPECIFIC EDITION QUERY
[A] AVAILABLE BUILD LIST
[P] PROJECT SUB MENU
[E] EXIT
By pressing R key you will have to choose between other options from a sub menu, for example you can choose to download builds from Fast or Slow ring of Microsoft Insider circuit.
Then you will have to choose the architecture.
You can download the build pressing D key, next you have to choose the desired language and the edition you would like to download (if all editions or a specific edition).

When the download will be completed the script will ask if Leave Updates for Integration and next if you want to delete the temp folder.
If you want to create the ISO image from the files just downloaded you need to use another tool called UUP Converter because as you can notice the files are in .ESD format.
Download latest version available from the link above and extract files from the archive in the same directory of UUPDL BEFORE download the build with uup.downloader.cmd, in this at the end of the process the UUPtoISO tool will be detected and you will be prompted if you want start it.
It will show a menu with the following options:
1 – Create ISO with install.wim
2 – Create install.wim
3 – UUP Edition info
4 – Create ISO with install.esd
5 – Create install.esd
After the creation process of the image you will fild the .ISO file inside the program folder, then you can delete the uup folder that contains the files downloaded before.
At this point you can burn the ISO image on disc with a disc burner software or create a bootable USB device using the freeware Rufus and perform an update of your current Windows O.S. installed or make a clean installation.
Similarly to UUPD tool there is also another tool that allows you to download latest Windows 10 builds, it’s called UUP Dump Downloader and does the same job but using GUI instead of command line.