Clean Install Windows 10 from Windows 8 (resolve activation problem)

1. From within Windows 8, update to Windows 10
2. Activate Windows 10
3. Create Installation Media (Thumbdrive)
4. Boot from Installation Media, format disk and install Windows 10 again
5. If have problem activating - type "slmgr.vbs /ato" (without quotes)  from command prompt (as administrator)