Need Help, M230

Ok, so I know that this player is REALLY old in terms of today’s digital audio devices, but I’m misplaced my install disk for the player and, for some reason, some of the songs on it are not appearing to my computer.  I think this is because this is not the computer that I installed the MP3 player software on.  Am I wrong about the reason for the issue?  And if not, is there anywhere to download the software for this device onto my new computer?  Any advise that anyone can give me would really help!!!