Change iOS

[blue07]

I have iphone 3G. My question is when we will change the new operating system in iphone, will we lose all the datas (contacts, applications, pictures, etc)?? If not, how to make the datas still saved? I've ever changed the OS once, the datas lost. Now I'm affraid of changing the OS. Please help.

 

[Gregoris]

itunes backs everything up so you dont need to worry about that but the iphone 3g wont be getting more updates after the 4.2.1 but in case you need to restore for what ever reason itunes will save your data