Your iPod is linked to your old computer. Did you transfer all your music from the old computer to the new laptop?
Click here for instructions http://support.apple.com/kb/HT4527
If so then you can Erase and sync your iPod with the new laptop. Just then have to go and select what music to sync and you should be good and your iPod is synched with your laptop going forward. Remember an iDevice can only be synched with one computer.
If the iPod music is not on the new laptop and you no longer have access to the old computer
Then this may help