Hi guys I really need a step by step guide on how to restore my iphone 4s to factory settings. I have tried methods on other threads but it cant work. Firstly my os is 5.1.1 , itunes 10.7 , I put it in DFU mode using redsn0w and i tried to restore with the ipsw. I tried several times getting different errors (21,1600 and 3194 ) respectively.I would really appreciate alot if someone could help me out thanks (;