Hello and sorry for bad english. I just bought an iPhone 3G and it has installed "whited00r.com". I don't know exactly, it's first time when I use iOS. Also, I saw there Cydia. What I want: to restore iPhone to default iOS, without jailbreak and things like this. Just original. My question is how I can do that and what risks are? It's possible to no longer work after that? Or can not use the SIM card (because it's locked)? Many thanks.