Solve : 3000 songs?

Hello to all ,
Recently I bought an Ipod Classic 120GB with about 3000 songs on it . When I plug it in to my computer it automatically  shows in itunes with all its contents , I can sync , delete , create playlists ...basically do whatever I want ,but when I eject it , all the music goes with the Ipod , Itunes is not allowing me to keep those songs in my Itunes library. The reason I want to sync all that music to my computer is that this is used Ipod and I would like to restore it , but if I do that with all the songs on it without back up I will loose them forever . My QUESTION is : how can I transfer those music files to either Itunes or my computer so they will STAY safe while I reset my Ipod ?
Thanks very much for any suggestions Simple all you NEED to do is enable the ipod to use external hard drive MODE then go into My Computer, click on the ipod drive letter, you may need to show hidden files by going, tools, folder options, View tab, click show hidden files and folders.

Now you should see a hidden folder in the ipod which should be CALLED Ipod Control in that will be Music and in that will be lots of folder like F01,F02... in those folders is your music.

Copy the whole music folder to your desktop.
Sync the iPod with your pc
Then reimport the music into itunes.

Problem Solved.