It's very necessary to backup your phone, newbielink:http://www.coolmuster.com/android/android-backup-assistant.html [nonactive]
could backup almost everything from your phone to computer.
Step by step tutorial:
Step 1: Connect your phone to computer and start the app, you should enable USB debugging on your phone, then click "Allow" on your phone to allow the program super user authorization when an Superuser Request pops up. The app could detect your phone automatically.
Step 2: Select data to backup
After the detect, all files on your phone will shown on an interface, and displayed in clear categories, select and check those you want to backup.
Step 3: Now you just need to click "Export" to start the work.
A wide range of Android brands are supported by this Android managing tool, including HTC, Samsung, Motorola, Sony, ZTE, LG, HUAWEI, Dell and many more.