iTunes transfer problem

Hi,
I'm upgrading a mate from XP to Windows 7 on a new PC. His iTunes program works as normal on the XP and his music is in the default iTunes folder.
However, when I copy and paste this folder into the new pcs iTunes folder it looks like all the albums are there but there ISN'T any music files. When I check the transfer drive it shows 72Gb but there's no music in any folders.

Can I say, I have transfered iTunes on a number of occasions in the past and never had a problem before.

 

Edit:

Even on the XP pc, the default iTunes folder doesn't show any music files inside each album folder.