I have an iPhone 4G that I bought at a yard sale for $10. When I got home and recharged it, I found that it was locked. I haven't a clue as to the password. Is there a way to completely reset this device and start with the factory settings? I'm using Win 7. When iTunes comes up when I plug in the phone to my laptop, it asks again for the password so I don't think I can do this through iTunes.