What kind of computer is it? Retail or home built? Was the drive added after you bought the pc or did it come from the factory? Some things to check is go into the BIOS and see what if it recognizes the drive. Other than that check to see if the jumper setting on the back of the drive is set correctly (i.e. master slave cable select). Other than that, Altex and other online stores sell DVD drives fairly cheap, around $30 if your feeling frisky about changing it out. ;)