Reply to Files can not be played :( (Traktor problem)

So i bought a toshiba satellite over the summer with the intention of using it at house parties/ frats and the like (i'm a college student). But the main problem I've had with it is that traktor refuses to read any of my songs. I transfered everything over from my mac to pc via crossover ethernet cable, so it all shows up in the proper file folders and in itunes, but traktor still wont play them. Any ideas as to why this is happening?

--The error reads:

File can not be played

FIle can not be played; may be missing, corrupt and unsupported.