Hello,
If you’re running a windows emulator and it’s asking for a bootable device, it’s asking for a windows 11 installation ISO, that needs to be put into a storage device with a bootable device creation software like rufus.
You can download windows 11 through this link.
You can use the provided links to setup your bootable drive or use the third party app rufus to set this up.
Hope this helps,
JC