Not so long ago a method was released to sync or manually manage/transfer your music to your iPhone/iPod between two computers, this method was grabbing the iTunes persistent ID from the master library and inserting it into the secondary computers iTunes edited library file with a Hex Editor.
However since the release of iTunes 10+, this method no longer works. I’ve been messing around with the same method for a while but to no avail it really does not want to work, some people claim reverting back to iTunes 9 fixes this problem, but what if you want the latest iTunes along with being able to manually manage your music and sync to your iPhone from two computers.
The method I’m going to teach you now is indeed even simpler than before. I’ve also been able to sync the same iPhone on my PC (Windows 7) and Macbook Pro. First things first, identify which is your main computer/library that your iPhone/iPod is already synced too. We will refer to this as the master library.
Firstly connect your iPhone to your main computer/library, and tick “Manually manage music” and hit apply, now disconnect your iPhone from the main computer. Now what you need to do is copy all the files within:
PC – Libraries > Music > iTunes >
Mac – User > Music > iTunes >
Copy them to a USB memory stick or any other way you can transfer them to another computer.
These files contain your iTunes library persistent ID and XML
Now head on to your secondary computer/library, make sure iTunes is closed. Navigate to the same directory and make sure you delete the files, paste the copied files from the USB memory stick in the same directory so you are pretty much replacing the secondary iTunes Library Files with your main iTunes Library Files.
Don’t connect your iPhone just yet.
Open up iTunes, watch the iTunes Folder we opened earlier. It might create a “Previous iTunes Library” folder, delete this. Now connect your iPhone/iPod to the secondary computer, you should now see it in iTunes with the “Manually Manage Music” option already ticked. You can now manually manage your music between both computers.
Note: You might notice your master computer library entries on your secondary computer, select all music and hit delete, when iTunes asks you if you want to remove them from your hardrive, click “No” as you may have some of the files you won’t want to delete.
This tutorial is for educational purposes only, I have not fully tested all possibilities so I do not take any responsibility for any damage you cause. Remember to backup your files first.