I did this recently and it was driving me up the wall!!! Thanks to fo3nix' instructions I did the following:
What I did was save the iTunes folder from my 'Music' section to an external hard drive and then downloaded the latest version of iTunes on the laptop. I then connected the external hard drive to the laptop and dragged that folder into the empty library and once it's loaded all your music, click 'consolidate library' and this will copy everything into the empty folder and hey presto, everything worked!
It may take time copying it onto the hard drive initially depending on how many tracks you have!! It took me an hour as I had over 3,500 tracks!! (That's half hour either way!!)
If you have things like videos or other tracks bought from iTunes, you may need to de-authorize the old one from the PC, under the 'advanced' section as these will need authorizing on the laptop when you finally want to play them!
Hope that helps!