First, you need to Enable your Windows 10 devices:

1. On your device that you want to enable, go to Settings. Choose Update & security, then choose For developers.
2. Choose the level of access that you need - to develop UWP apps, choose Developer Mode.
3. Read the disclaimer for the setting you chose, then click Yes to accept the change.
4. in the Developer Mode features enable Device Discovery.

Then Create a Microsoft account and use "Windows Phone Developer Registration" tool for registering it on your pc. It can be found in the following address:

C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Windows Phone SDK 8.0