Yes, licenses today are attached to your M$ account. Back in the days they where attached to a MAC address, but even back then you could call M$ and ask them to detach a license from a certain MAC address, which would allow you to install the software on another device.
Use it for software tho, the Windows license itself is included in your server price and tho you may be able to use custom ISO's to upload your own Windows ISO it might not be an optimal solution to do so.
