I recently got a 3GS and tried out jailbreaking for a while and would now like to go back to regular just because I'd like to feel safer about the warranty. I've been having so many problems when trying to restore. I'm using 3.0.1 and trying to restore from ipsw files that I have from a tutorial that I used to jailbreak. I keep on getting error 4 when trying to restore, and it's beginning to scare me. How do I get my iPhone back to normal?