It has been the same since Vista, you can do a clean install using the upgrade disks
If the installation detects the presence of a qualifying OS then the upgrade will activate this is what should happen if you boot from the upgrade and blow away the partition that contains a windows xp/vista/7...
It is essentially the same thing and you should be able to use DVD burn program to create iso from it
My preference is to create the ISO file from the download then create a bootable USB from that, having the ISO allows me to make DVD or USB at anytime