Background- Recently I got the factory unlock confirmation from at&t for my jailbroken locked Iphone 4 (ios 5.0.1 & BB 4.11.08). I connected it to itunes and got the message that "Congratulations Your Iphone Is Unlocked" , earlier the itune was not detecting my iphone. Per the at&t email , I was following the steps to complete the unlocking process but got the error 21. While reviewing this forum I come to know that I should put the device in DFU mode . I did that now , while restoring the iphone , I am getting error 1601. I have tried everything available on google result . - I have uninstalled the itunes many times - (searched and deleted everything from apple) , still getting 1601 or 1602. - Changed the uSB port - Restarted There are many tutorials available to for IREB and Redsn0w for custom IPSW.Since, I do not have custom IPSW (or I am not sure 100% about this) I do not think it is of my use. My confusion is - As of now I wanted to take default factory settings with latest ios 5.1.1. What steps should I follow to fix the error 1601/1602 and get my iphone restored on 5.1.1 with default factory setting. I am not worried to preserve anything here data,BB,jailbreak ,application etc. I am new to iphone and got this as a gift from my cousin from US , but using it as ipod for the last 3 months . Please help me to fix this issue ... Please !