I want to do a complete clean restore on a 3GS which is version 4.2.1 and want to update to at least iOS5. What is the best software to do that? I heard RedSn0w? But last time I remember correctly, if I used RedSn0w and if I shut off my iPhone, I won't be able to boot it up again until I use a computer. I want to be able to restart my iPhone without going back to my computer.