If you want to update the software on your mobile phone, it's recommended you back up the phone memory. Remember, you need to install iTunes on your computer before you can back up the phone memory. You can download the program from www.itunes.com.
Connect your mobile phone and computer
Start iTunes on your computer.
Back up phone memory
Connect the data cable to the socket at the bottom of your mobile phone to the computer's USB port.
Depending on your settings in iTunes, backup may start automatically.
To start backup manually:
Right-click your mobile phone in the menu to the left.
Select Back Up.
*Please refer to the Apple website for more information or further support.*