The iPhone 4 was jailbroken at version 4.2.1. So, I was going to update it to the newest iOS 6, but I don't know anything about restoring iPhone. I started resetting the phone in the settings>genetal>reset>clear contents and settings. I finally realized that I've did it wrongly, I shouldn't reset a jailbroken iPhone. After that, it is stucked in the booting loop. I've done the DFU thingy and restoring it now, but I have no idea about am I doing this right? Or should I do it another way?