Introduction: Sync IPhone With Another ITunes Library Without Erasing Data (2 Steps)
"The iPhone is synced with another iTunes library. Do you want to erase this iPhone and sync with this iTunes library?" You may have received this warning message when you were syncing your iPhone with iTunes on computer. Actually, this is one common iTunes sync problem you may meet when you sync your iOS device on a different computer, or with another iTunes library on your laptop.
In this situation, if you don't want to erase your iPhone, you have to stop sync your iPhone and to find a available way to transfer multiple iTunes library without losing data?
Tool to Transfer iTunes Library to iPhone without Erasing Data
AnyTrans is an all-in-one iOS content manager, which you can use to transfer 20+ iOS data files across any iOS devices, computer and iTunes. With this tool, you can easily copy any iTunes library to your iPhone without erasing data. In addition, you can also use this powerful tool to access your iTunes/iCloud backup, and delete some data you can’t directly remove from your iPhone, such as synced photos.
2 Steps to Transfer iTunes Library to iPhone with AnyTrans
Requirements: your iPhone, one USB cable, one computer with iTunes, AnyTrans.
Step 1: Scan Your ITunes Library and Your IPhone
Run AnyTrans on computer > Connect iPhone to computer via USB cable > Click “iTunes Library”. This software will automatically scan your iTunes and iPhone data.
Step 2: Select Files and Transfer From ITunes to IPhone
Choose the data you want to transfer > Click “To Device” button at the top-right corner to copy selected items from iTunes library to iPhone.
Note: Before you sync with iTunes
You’d better know some common iTunes sync problems to avoid data loss before transferring iTunes library to your iOS device with iTunes. If you find this guide is helpful, please share it with your friends.
Source: http://www.imobie.com/support/how-to-fix-iphone-is-synced-with-another-itunes-library.htm