How to copy songs from your iPod to your PC
Connect the iPod to your PC. If iTunes starts syncing (ie erasing) your music automatically, hit the "X" in the upper right hand corner of iTunes display, to the left of the search box, to stop it. In Control Panel, Portable Media Devices, double-click your iPod. Navigate to the Music folder. Select all the music folders, and drag and drop them into a folder on your hard drive, or directly into iTunes.