Hello everyone, My iPhone 3g recently ran out of battery. When I tried to charge it nothing would come up on the screen. I plugged it into the computer with iTunes open and it was recognized by iTunes immediately. A popup came up and said that the iPhone was in recovery mode and needed to be restored. During the restore an unknown error 21 came up. I tried disabling security features on my computer as suggested by apple but it is still not working. Any Suggestions?