I have 100gigs of music so I successfully transferred my iTunes media to an external hard drive, and identified this new location within iTunes/Preferences/Advanced/Location. Everything worked great until I had to shut down and start up. Now, it no longer recognizes the media library. When I try to play a track in iTunes, iTunes says the original file could not be found. It prompts me to locate this one track, which I do, and that one track will play. All of the other tracks have the (!) sign next to them in my iTunes library. I have double checked the settings in my iTunes preferences, everything appears to be configured as when I first made the successful transfer (identifying the external hard drive as the location). I've made sure to restart once the external hard drive is connected. Any ideas on how to regain access to my library on my external hard drive would be appreciated.