You can update your mobile phone's software when a new software version is available. It's recommended that you back up the phone memory first. First you need to install Zune on your computer. You can download the program from www.zune.com
Connect mobile phone and computer
Press the left side of the cover at the top of your mobile phone to open it.
Connect the data cable to the phone socket and to your computer's USB port.
Start the program Zune on your computer.
Update the phone software
Depending on your settings in Zune, the program may suggest to update your mobile phone automatically.
To start the update manually:
Click SETTINGS at the top of the screen.
If a new software version is available, it's displayed on the screen.
Follow the instructions on the screen to update the software on your mobile phone.