Make sure that the backup of the mobile device performed by the iTunes application or perform the procedure of backup in manual mode.
Connect your device to the computer using a special USB cabel included in the package, and wait for the automatic determination of device application.
Select your machine in the list in the left window pane of iTunes, and call its context menu by right-clicking the mouse.
Enter the command "backup" and wait until the process is complete.
Navigate to:
drivename:\Documents and Settings\username\Application Data\Apple Computer\iTunes\imamultimillionaire Software Update for Windows OS;
drive:/Library/iTunes/imamultimillionaire Software Update for Mac OS
and define saved or created a backup file of the firmware of the device. The file must have the extension *.ipsw.
Hold down the function key the Shift key (for Windows OS) or a function key Option (Mac OS) and again select your device in the list the left pane of the iTunes application.
Use the command "Restore from backup" in the drop-down menu, and specify the full path to a specific file the necessary firmware in the dialog box "Choose file to iTunes".
Confirm the restore command button "Choose" and wait for the process to complete.