My iPhone 5 is not recognized on any PC, wont charge by USB in PC either

My iPhone 5 is not recognized on my PC w/ Windows 7, nor Windows 8. It does not charge while plugged into either computer, but it does charge when plugged into the wall! I tried uninstalling, downloading a new copy and installing iTunes on both PCs. There is no sound when I plug the iPhone into the computer. Device Manager does not have an entry for any Apple device anywhere. Am I screwed? There is one thing: I have not yet updated to the latest firmware, but I have been holding off because its been a long time since I backed the phone up. I'm really worried!!! Please help, I'm out of the 1 year warranty on it.