I'm having this exact same issue on a brand new install of Windows 10. I created my USB key with the Windows 10 Update Wizard that downloaded the Win10 ISO from Microsoft and created the bootable USB key. I've installed twice with the exact same results. Windows 10 can't be activated and I also noticed the Windows 10 Update services is stuck at 'Starting'. I've left it running overnight and it never starts. It does this from the very first boot after install. I've tried stopping it with taskkill and restarting and it still freezes.
Edit... Should also add that I've tried a ton of different steps to fix Windows Update with no success. I'm lost and at this point wish I would have just stayed on Windows 7.