how do i get my old itunes back

Yes, there is an official Apple Knowledge Base article at http://support.apple.com/kb/HT1329 which describes what you need to do. I hope it helps. Let us know if you get it to work!

Download itunes again and plug your ipod in. A box should come up that recognizes that you have music on your ipod and will ask if you want to transfer your purchases onto your computer. Having said that, there is no way to get music back from itunes unless it's still on your ipod or an external harddrive, and any songs on your ipod that weren't purchased from itunes cannot be transfered back- they can only remain on your ipod, so make sure it's set to manual so you don't lose them.

Oops, those instructions I pointed out are for transferring from one computer to another, not restoring from just the iPod. Sorry.

*Recover media from iPod*
Check out this post from Zevoneer for options on moving your iPod data back to your computer.
http://discussions.apple.com/message.jspa?messageID=9935961#9935961

tt2