Restoring from Backup error - cannot be saved to computer
This may also be a software issue, you can attempt getting your iPhone into DFU Mode in order to restore not only your contects...etc... but also reinstall iOS (as it may have installed incorrectly).

As it is stated at this webpage: "


  Entering DFU Mode (Official Instructions)


Plug your device into your computer.
Turn off the device.
Hold the Power button for 3 seconds
Hold the Home button without releasing the Power button for 10 seconds
Release the Power Button but keep holding the Home button
Keep holding the Home button until you are alerted by iTunes saying that it has detected a device in Recovery Mode


"

Then you should be able to click the restore button, and restore correctly.

Hope this helps.