The first beta version of Windows 11 is out now, but so far, it’s only available as an update for Insider members. This limitation can be circumvented by compiling the ISO image of the system itself and installing it in the usual way from the installation drive.
Create Windows 11 ISO image ISO
First, you need to use UUP dump site. Find the desired build of Windows – in this case. It is called Windows 11 Insider Preview.
Pay attention to the architecture of the OS. Select the system language, then the edition (for example, Home or Pro). Check the box “Download and convert to ISO,” then click on the “Create download package.” A small archive will be downloaded immediately after that.
Unpack the resulting archive and run one of the scripts with the “uup_download” line in the name, depending on which system you are using.
First, downloading files from Microsoft servers will go, after which they will be converted into a finished ISO file. This file can be found in the source scripts folder. Now, this system image can be written to a flash drive using any convenient program like Rufus.