If using windows...
Temporarily disable your firewall and antivirus software and try again...
http://support.apple.com/kb/TS1379
See iTunes Connection Issues here...
iTunes for Windows: Troubleshooting security software issues
Anibele wrote:
Iam trying to restor my Ipad2 but there comes the error (16)
What that means??
Check for hardware issues
Related errors: 1, 3, 10-47, 1002, 1011, 1012, 1014, 1000-1020, 1669.
Try to restore your iOS device two more times while connected with a cable, computer, and network you know are good. Also, confirm your security software and settings are allowing communication between your device and update servers.