Your computer (not iPhone) needs to be connected to the internet in some way. Either by Wi-fi, ethernet or whatever. If your computer isn't online then iTunes can't talk to the servers it needs to to verify your activation.
Your computer (not iPhone) needs to be connected to the internet in some way. Either by Wi-fi, ethernet or whatever. If your computer isn't online then iTunes can't talk to the servers it needs to to verify your activation.