Using Boxes

Hi and welcome. Crucially for any VM to work you need 8 Gb RAM in your machine, and allocate 4 Gb RAM to your VM. Not sure if enough for Windows 11 though:

I've not tried Boxes. My preferred VM software is virt-manager. Initially on a different OS I had installed Windows 7 Pro as a .vhd in Virtual Box. I moved to a different OS, installed virt-manager and imported the .vhd file to make it a .qcow image. I was even able to upgrade it to Windows 8.1 Pro. I would give virt-manager a try. Now if you are trying to install the 24H2 version there are some workarounds needed: