Problems connecting with getting software for iphone (5.1). Cannot restore factory settings.

Hi.

I have a 1,5 year old iPhone. I've tried to update to 5.1 but I keep getting the massege cannot connect to the network.I get the same massage when I try to restore factory settings. My internet works. I do not have a firewall on. Everything (iTunes, OS system) is up to date. No orther USB is connected to my MacBook Pro. I've tried restating my MACBook and phone. I also tried restarting my phone by holding ind the home botton while conneting to my mac. Nothing seems to work. What shouls I do.

Thanks

D