I bought my son a macbook pro to replace his old macbook as the CD/DVD drive didn't work. He wants to retain the HDD from the macbook as a back up as it has thousands of music tracks on it. I bought a new HDD for the macbook intending to load a new version of Snow Leopard on it so that I can sell it on. As the CD/DVD drive is U/S I am using an external CD drive but the macbook does not seem to recognise the external drive. Can anyone please point me in the right direction as to how I can do this as I am clearly nissing a trick somewhere!