The steps below should help you update your iPhone to iOS 6 and activate it with your carrier.
As part of the update and restore process, iTunes will (in order):
- Back up key elements of your device, such as settings, Contacts, Calendars, Notes, and your Camera Roll1. iTunes will not, however, back up media content from your iOS device, such as music, apps, books, movies, and TV shows.
- Update your device to the latest version of iOS software.
- Restore your device from your most recent backup.
- Restart your device.
- Sync back media content from your iTunes Library to your device2.
Your iPhone may display one of the following messages when you attempt to activate it:
- "Your iPhone could not be activated because the activation server is temporarily unavailable."
- "The iPhone is not recognized and cannot be activated for service."
- "iTunes was unable to verify your device."
Perform the following steps if you receive one of the messages above:
- Restart the iPhone.
- Try another means of reaching the activation server and attempt to activate.
- Try connecting to Wi-Fi if you're unable to activate using a cellular data connection.
- Try connecting to iTunes if you're unable to activate using Wi-Fi.
- Restore the iPhone.
If you receive an alert message when you attempt to activate your iPhone, try to place the iPhone in recovery mode and perform a restore. If you're still unable to complete the setup assistant due to an activation error, contact Applefor assistance.
I hope this information helps ...