Q: I store my music on a removable hard drive with my laptop. My problem is that iTunes does not know where the music is at once the drive has been removed and then hooked up again. What can I do to make iTunes know where my music is stored besides going through each song and showing iTunes where to look?
A: In order for iTunes to work with a library on an external hard disk you have to first choose the appropriate music folder in iTunes Advanced preferences.
Then, you must connect and mount the hard disk before launching iTunes. If you do this, iTunes will have no problems finding your music. If, however, you connect and mount the hard disk after iTunes has launched, the program will have already looked for your music and not found it.
You should also quit iTunes before you unmount the drive to avoid any such problems.