- 10 Minutes of your time
- On iPhone, iPod Touch, or iPod (Repeat for all devices you wish), select “Manually mange music and videos”
- Backup of iTunes Music
- iTunes closed
- Ability to find your iTunes folder: in Windows XP, its default location is in “My Music” and, for both Windows Vista and Mac OS, it is located in “Music”.
- Download HexEdit for Mac or UltraEdit for Windows for the secondary machine with which you wish to sync
- Knowledge of how to open a file with the editor downloaded in the point above on both Windows and Mac (however, you do not need to if using Mac to Mac).
On the Primary Computer (with which the iPhone, iPod Touch, or iPod was first synced):
- Make sure iTunes is CLOSED!
- Backup the iTunes Library on the machine with which you wish to sync. Backup “iTunes Music Library.xml” and “iTunes Music Library” (or iTunes Music Library.itl on Windows). It is important that you back these files up to a safe location because we will be modifying the files.
- Retrieve your iTunes Library ID. Open “iTunes Music Library.xml” with a text editor (TextEdit on Macs, Notepad on Windows). Find the entry after
On the Secondary Computer:
- Make sure iTunes is CLOSED!
- Retrieve your iTunes Library ID. Open “iTunes Music Library.xml” with a text editor (TextEdit on Macs, Notepad on Windows). Find the entry after
- Replace the the iTunes Library ID, in my case 0E958526D15C67FA with the one from the computer (8B6C633F7DACB74B-iTunes Library ID from the Windows machine) the iPhone is already syncing with. Save the file, then close it.
- In Hex Editor open “iTunes Music Library” (iTunes Music Library.itl on PC)
- Choose “Find and Replace” from the Edit menu. Make sure the “Hex” matching is selected not ASCII. Find the iTunes Library IDs you found from both the primary and secondary computers.
- In the “Find” section, enter the iTunes Library ID of the secondary computer and, in the “Replace” section, enter the iTunes Library ID from the primary computer. There should be one match. Save the file and close.
You should now be able to sync your devices with two or more computers. Now, you will not be alerted by the annoying “Erase Your Data” prompt from iTunes.