Windows 10 IoT Core Commercialization
Signing Up
https://www.windowsforiotdevices.com/
IoT Core manufacturing guide
https://docs.microsoft.com/en-us/windows-hardware/manufacture/iot/iot-core-manufacturing-guide
Feel free to comment if you can add help to this page or point out issues and solutions you have found. I do not provide support on this site, if you need help with a problem head over to stack overflow.