Apple 4/4S/5 upgrade iOS7 when it's disconnected from the computer, the system can't upgrade.

Problem phenomenon

My mobile phone in the upgrade ios7.03 time with the computer disconnected system upgrade to half not move, how to do is not moving.

Problem solving

First, shut down and turn on the computer and connect to itunes again.
Second, if it can't be solved, the phone goes into DFU mode, then connects the computer to open itunes to restore your device!
About DFU:
1. Connect the iphone to the computer with a USB cable, and then you will hear the sound of the computer connected successfully. Next item
2. Now please turn off the iphone first, then you will hear the computer is not connected to the successful sound of the message.
3. Please hold down the switch machine key and the home button at the same time, continue to the first 10 seconds, please release the key immediately, and continue to hold down the home key.

4. itunes starts automatically at this time and prompts you for a recovery mode (the iphone will remain in a black screen state). Then you can hold down the SHIFT key on the keyboard and click "Restore" to select the appropriate firmware to recover