How to sync iPhone or iPad with multiple computers
Despite the simplicity of using the iPhone and iPad, Apple sets a very nasty limitation: you can synchronize a device with multiple iTunes libraries. Connecting the gadget to a different computer, you will see a message that your iPhone or iPad can be synced with only one library, otherwise users could share files, paid software and even music. But this limitation, if desired, can be circumvented.
The algorithm for determining the home iTunes library is hidden in a single file on your Mac or PC. It’s enough just to copy it to another computer to re-use iTunes “its”. We will explain how to do this on a Mac, but for Windows manual is almost exactly the same.
Open Finder, press a familiar combination Command+Shift+G and specify the path to the iTunes folder: ~/Music/iTunes.
After opening the folder make a backup is strongly recommended in case of adverse outcome.
Open the file iTunes Music Library.xml by TextEdit, find the key of the library (highlighted below). Copy it or write down somewhere- in the future we need it.
On the computer you want to sync an iOS device, you must do the same operations. The files in the folder named Previous iTunes Libraries you want to delete.
Then just replace the key in the file iTunes Music Library.xml the key from your library. Then open the iTunes Library file.itl and delete all its contents. You can connect the device! Ignoring the error message, you can safely use your iPhone or iPad.
In Windows the only difference is that to edit the files you need to use TextEdit, and “the Notebook”, and the iTunes library in this case is located at C:UsersUSERNAMEMusiciTunes.