How do I stop iTunes from erasing audio files from my iPod?

All audio files stored on an Apple iPod can be erased when the iPod is connected to a new or recently re-formatted computer or hard drive. The contents of the iPod correspond to audio files added to the iTunes music library on exactly one computer: the first computer to which the iPod is ever connected. When the iPod is connected to a different computer running iTunes, all audio files stored on the iPod can be erased to exactly match that computer's music library, no matter what the number of audio files in the computer's music library.

If you re-format your computer's hard drive and re-install the operating system, all audio files and the iTunes music library stored on your computer will be erased. You could potentially erase the contents of your iPod the first time you connect it to your computer. This also applies if you purchase a new computer, replace the hard drive of your current computer, switch the music synchronization option on your iPod from manual updating to automatic updating, or completely reset iTunes to its default settings.

To properly back up the audio files stored on your iPod and restore them to a new or recently re-formatted computer or hard drive, see the Apple knowledge base article How to use your iPod to move your music to a new computer.

Note: To back up audio files in the iTunes music library and the library itself, the Apple article instructs you to save the entire iTunes folder to the iPod. However, this will not work if the iPod is more than half full.

Two files inside of the iTunes folder store various attributes about the music files not stored in ID3 tags:

• iTunes Music Library.xml
• iTunes Music Library.itl

In Windows Vista, both files are located in <hard drive>:\Users\<user>\Music\iTunes.

In Windows XP, both files are located in <hard drive>:\Documents and Settings\<user>\My Documents\My Music\iTunes.

Audio files are stored inside of the iTunes folder, located in the iTunes Music folder.

Copy the iTunes folder that contains the two files and folder from a host computer or hard drive, and copy it back to the same location on a new or re-formatted computer or hard drive. This folder is created the first time iTunes is run on a computer. Be sure to overwrite the default version of this folder with the backup you made.