My sister had given me her iPhone 3GS just over a year ago so she could get a different phone. My parents started complaining about the data base charges. So i was forced to change phones and put my sim in a different one. I still used the iPhone all the time as an iPod, to play games, ect. Until recently, my iPhone needed to be restored. After it finished restoring, It said "No SIM Card Installed. Insert valid SIM with no PIN lock to activate iphone". It hasn't ever said this before. Can anyone tell me how to fix this problem, without putting my sim card back into the iPhone?