hi. I have a Sony Barracuda and a Maxtor hdisks. Both has xp pro os because i am trying to make the new Maxtor as my OS and will reformat the Sony that has an OS too to be my backup hdisk. I am trying to make Maxtor the primary master and Sony the primary slave but it can't see it when you open the win explorer. when it boots it can see both the hdisk. I had tried jumper for master for Maxtor and slave jumper for Sony but problem still exists. I also tried cable select, Maxtor on the far end and Sony on the middle - no good. BUT, when i make the Sony the primary master and Maxtor the primary slave, both hdisks appear. what could be wrong? why can't i see the sony hdsik if my primary master is the maxtor?