Cubase Studio 4, PC to Mac

Hi, any help for this one much appreciated. So I have a load of songs on my old PC but want to load them up on my new Mac. I put them onto an external hard drive formatted for my Mac, opened up Cubase 4, loaded up a particular folder/song but then it comes up with “Resolve Missing Files.” Basically the structure of the songs are there with each track but audio for each track is absent. Am I trying to do something thats not even possible here?