Change your host file. Quick google search with that error # will give you instructions. It's easy. I upgraded and it works great.
Or update or restore in either case. No specific requirement to do it either one in either situation really.Update if running iOS 6. Restore if running any iOS 7 betas. iTunes 11.1 doesn't matter unless you are planning on restoring an iTunes backup. Just use an iCloud backup.
Update if running iOS 6. Restore if running any iOS 7 betas. iTunes 11.1 doesn't matter unless you are planning on restoring an iTunes backup. Just use an iCloud backup.