I can't enable iMessage after installing iOS7

Hi glcaputo,

Thanks for visiting Apple Support Communities.

If Messages isn't able to connect to the internet, I'd first try the steps in this iMessage activation article:

iOS: Troubleshooting FaceTime and iMessage activation

http://support.apple.com/kb/ts4268

To resolve this issue, follow these steps. After each step, turn FaceTime and iMessage off and on in Settings > Messages and Settings > FaceTime.

1. Ensure that you have an active Internet connection. You can complete activation using Wi-Fi or a cellular data connection. If you need help connecting to Wi-Fi, follow these steps.
   
2. Update to the latest version of iOS.
   
3. If your Apple ID isn't an email address, you can change it. The Apple ID that you're using to activate FaceTime or iMessage must be an email address. For more information, see how to change your Apple ID.
   
4. If you get an error when you try to sign in to your Apple ID, sign in to your account and ensure that the primary email address has been verified. If verification is pending, follow the instructions in the email that was sent to that email address to complete verification.
   
5. Ensure that FaceTime hasn't been restricted: tap Settings > General > Restrictions > FaceTime.
   
6. Ensure that your iPhone is set to the correct time zone: tap Settings > General > Date & Time.
   
   Note: If Set Automatically is on but the incorrect time zone appears, turn Set Automatically off and choose the correct time zone, date, and time.
   
7. Enable iMessage and FaceTime while connected to another Wi-Fi network in a different location.

You can see that you've activated FaceTime and iMessage with your Apple ID by tapping:

• Settings > FaceTime > You can be reached by FaceTime at:
• Settings > Messages > Send & Receive > You can be reached by iMessage at:

Regards,

Jeremy