I have an external HDD, which has a backup of iTunes from my old windows machine. It consists of 3 directories, which are date stamped, the newer folders containing new or changed files since the last backup. I literally got my rMBP a few hours ago, and am trying to restore my iTunes library onto it. The first part was easy. I got rid of the existing iTunes folder, then copied the oldest one from the external drive onto the Mac. The problem is copying the second and third ones on. If I drag the newer iTunes folder from the external drive to the Music folder on the Mac, which option should I choose? I'm running Mountain Lion. I tried it with a folder in whatever My Documents is called and a folder on the desktop. It didn't work as expected though, because the files that were in the destination folder, but not the source went missing.