I have recently upgraded to Itunes 10.4 on my Windows 7 computer. I wished to perform an incremental backup of my music. The help file said click on File - Library - backup... But the word Backup was not there. I phoned Apple help line and spent a great deal of time with a very helpful advisor who could not help. I was then connected to a supervisor who confirmed that the word Backup was missing on his computer as well. He suggested that I could back up by right clicking on a playlist. I have 24 playlists this would take ages. BUT it still does not allow me to back up incrementally.