Create a Setup USB drive from https://www.microsoft.com/en-us/software-download/windows10
Create a file named PID.txt in the Sources directory, with the following contents:
[PID] Value=VK7JG-NPHTM-C97JM-9MPGT-3V66T
Boot from this USB drive
In order to start the phone activation please type “SLUI 04” in the search box on the taskbar and press “Enter”. Then follow the instructions on the screen to activate Windows.