Microsoft to Revamp Activation System with Windows 9@ 2014/07/08
The way we understand it, it works like this. After paying for your license while logged into the Microsoft Store, you're made to download a generic install disc image. After its installation, your machine's details (usually just motherboard-related details) are logged with Microsoft, and the software stays activated on your machine. When you need to install your OS on another machine, you untie your current machine from your licence online, and install your software on the new machine. The software will stop working on the older machine, ensuring that only one single-user license is running on a machine at a given time. The concept can be suitably adapted for 3-user and 5-user family licenses.