An iPod or iPhone can be connected to a PC for data transfer using iTunes. There may be problems in transferring data from the PC to the iPod due to iTunes sync issues. An error stating that iTunes is synced with another library is a common sync issue. This problem can be solved by not allowing iTunes to sync at all when the iPod is connected to the PC. Instead, the settings need to be changed to allow restoring factory settings on the iPod. All data and information will have to be backed up using the appropriate options. Once the iTunes sync issue is solved, all the data can be transferred back to the iPod.
I went to download a CD to my iPod via iTunes. I needed to update to the latest version of iTunes, which I did. I then hit sync to download my CD to my iPod and a message came up saying that my iPod is synced with another iTunes library and says I must erase and sync it. I have only used this computer to sync so I don't know how I am on another library. I don't want to erase all the music on my iPod in order to add new songs. How can I avoid this?
You've probably already found an answer for this issue, but I will post this for any other person who is facing the same problem:
Upon plugging the device into your computer/laptop, it will give the message you were stating. Do not allow it to sync to your current library AT ALL.
Rather, click on the summary tab that displays when you've clicked on the iPod/iPhone on the menu bar on the left. The summary and general information will be on the right hand side of the screen.
Once you are in the SUMMARY TAB:
Click on backup and there are three rows: iPod, Version and lastly, OPTIONS. There are four selection boxes. Click on the last box labeled "Encrypt iPod/iPhone backup" or you can also select this option by clicking on the change password box.
Put in your iTunes account password: it seems to be synced that way and always works. If you are prompted to update your iTunes software in the process, do it. It is better to have the updated version and have it function smoothly during this transition.
This will backup everything on your device without losing your information permanently.
Once this step is complete, you will indeed need to restore the device to factory settings. Please note that this is the only systematically correct method I know of to successfully re-register your device back into your library.
After the factory settings are restored...IT IS TIME TO PUT YOUR MUSIC, Apps, etc. BACK IN.
This will take some time and will cause your device to switch off and restart on its own.
A new screen will appear asking you to set up your iPod/iPhone.
You will see the backup on your screen and you should select the restore from backup option listed there. You will be prompted to install your password from the last time you backed up your computer (as stated before, this should have been the iTunes account password for the sake of consistency).
This backup should also take a few minutes.
Thanks to Dee for this tip on the forum