How can I sync my iphone to a new itunes?

Question

Im trying to sync my iphone with my girlfriends computer on a new itunes that she created for me, but it says i'm synced to another computer.  I have no access to that computer anymore so how do I un-sync from that computer and sync to my girlfriends?

Answer 1

Syncing to a new iTunes library or computer will erase your phone. Only if you back up your phone manually before syncing, you can restore your phone from that backup again. A manual backup does not include the sync process.
Set up your iTunes account, disable autosync in iTunes, connect your phone to your new computer and right click on it in the device list and choose backup. iTunes will backup your phone without syncing.
Transfer your purchases the same way, choosing "transfer purchases" this time.
When you connect your phone for the first time, all media content will be erased. But you can restore your settings and app data from your manual backup afterwards.
Don't forget to set up at least one contact and event on your new computer to be able to merge calendars and contacts when you sync the phone for the first time.
Music is one way only, from the computer to your device, unless you bought the songs in itunes and transferred your purchases.
There is 3rd party software out there, but not supported by Apple, see this thread: http://discussions.apple.com/thread.jspa?threadID=2013615&tstart=0
About backups and what's saved:http://support.apple.com/kb/HT1766
How to back up and restore:http://support.apple.com/kb/HT1414
How to download apps for free again:http://support.apple.com/kb/HT2519
Saving other data is also described here. How to back up your data and set up as a new device
Message was edited by: Ingo2711