o.k i dunno bout this stuff so please be sympathetic, got a new hard drive and a mate of mine decided to move some files about between the two, now i can't find my music, it's still the same size so it's in their some where

Try going to start/search and typing in *.mp3 or whatever your music extensions are. This will find all the music files on the computer. Works the same for any extension. By using the * you are telling the computer to look for all the files instead of a name of one song.