My understanding is that these disks are pretty much just a utility. If they do have a copy of a minimal OS, it is locked by a authorization key that is not pro

My understanding is that these disks are pretty much just a utility. If they do have a copy of a minimal OS, it is locked by a authorization key that is not provided. You must provide your own key, and the Windows license is tied to an individual machine and fully transferable for the life of the machine. Reusing licenses is a different problem, and one that also plagues full install disks.