Until recently, I’ve been running iTunes on a Windows XP PC but I’m in the process of migrating to a Mac OS X system. Whilst most data transfers have been straightforward, I found that, after moving the files to a disk that could be accessed by both the Mac and a PC (i.e. a FAT32-formatted external hard disk), getting iTunes to recognise my library was challenging. I’m sure it’s quite a common scenario so I thought I’d post what I did here so that it can be of use to others.

Whilst my scenario involved moving from iTunes 6.0.4 on a PC to 6.0.5 on a Mac, the principle is the same for moving iTunes music libraries between any two PCs (Mac OS X or Windows).

Apple’s advice for moving your iTunes Music folder is okay for moving files on the same system but their advice for switchers to transfer their iTunes Music Library files from PC to Mac just didn’t work for me (well, it works, sort of, but simply importing the music files into iTunes will lose playlists, history, ratings, etc. and importing the music library file itself will retrieve those items but won’t find the music files because they have moved location). I need to keep the selections because that’s how I determine what will be synchronised with my iPod – quite simply my 47GB music collection will not fit on a 4GB iPod Mini!

Luckily, the extensive article on moving iTunes libraries whilst preserving library data at the HiFi Blog gave me all the necessary steps (although they focus on libraries where iTunes is not used to organise the music – I let iTunes handle that for me). After setting iTunes preferences to point to a folder on my external hard disk (on the Advanced page, under General), I quit iTunes and edited the iTunes Music Library.xml and iTunes Library files that reside in Macintosh HD/Users/username/Music/iTunes/ (even though the music files are on the external hard disk, iTunes keeps its database files in the main user data location), removing all binary data from the iTunes Library file to leave a 0KB length file and replacing all instances of the original library location in iTunes Music Library.xml with the new library location (for me this was from file://localhost/C:Documents%20and%20Settings/Mark/My%20Documents/My%20Music/iTunes/iTunes%20Music/ to file://localhost/Volumes/EXTERNAL%20HD/Music/iTunes/iTunes%20Music/). I found the easiest way to edit the files was on the PC (using WordPad – depending on the size of the music library, NotePad may not cope with the file sizes involved). It’s also worth noting that on a PC, the iTunes Library file has a .ITL extension.

After making sure that the edited files were back in the Macintosh HD/Users/username/Music/iTunes folder and starting iTunes, I was greeted with an Importing iTunes Music Library.xml message before:

Organizing Files

The file “iTunes Library” does not appear to be a valid music library file. iTunes has attempted to recover your music library and has renamed this file to “iTunes Library (Damaged)”.

Actually that message is incorrect. On my system, there is no iTunes Library (Damaged) file but there is a Previous iTunes Libraries folder, which contains a file called iTunes Library 2006-7-12.

iTunes then continued to analyse and determine the song volume for 2344 of the 6766 items in my music library (I’m not sure what this actually means and it seems strange that it was not for the entire music collection) after which it was available for use as normal (almost) with all my tracks, playlists, selections, date last played, etc. I said almost normal because there are a couple of additional playlists (Podcasts and Videos) and the Podcast subscriptions don’t get migrated but that’s easy to fix. Again, it was the HiFi Blog article that helped me out – browse the library to view all music files with a genre of Podcast and drag them onto the Podcasts heading in the source column before clicking on resubscribe for each Podcast to enable new downloads (the existing downloads should all still be available).

The next step was to hook up my iPod which synchronised normally (I vaguely remember selecting that it was connected to a Windows PC the first time I set it up and expected to have to do some reconfiguration for the Mac but it seems that was not required). The only exception was for my purchased music, for which I received the following message:

Some of the songs in the iTunes music library, including the song “songname“, were not copied to the iPod “ipodname” because you are not authorised to play them on this computer.

I found this strange because I’d already accessed the iTunes Music store from iTunes using my Apple ID, and although there was a “Deauthorize Computer…” option on the Advanced menu, I couldn’t see an equivalent option to authorise it (so I naturally assumed it was already authorised). Attempting to access my purchased music in Front Row gave a better clue:

This computer is not authorized to play the selected song.

To authorize your computer, select the song in iTunes and enter the account name and password used to purchase the song from the iTunes Music Store.”

Sure enough, this did the trick, advising me that I had 2 out of a maximum of 5 computers authorised for my music and then allowing me to both play the purchased songs and synchronise them with my iPod.

After running with iTunes on my Mac for a few days now, everything seems to be working okay. The only remaining step is to deauthorise the original Windows XP PC from where I copied my music.