Ok, I played a little bit with xplorer360 extreme2 and I was copying files. Then suddenly xplorer froze and I had to re-open xplorer, but there were only partition 1 and 2. I had an old backup of partition 2 so I restored it. Now I only can see Partition 2 on xplorer and xbox says that hard disk needs to be formatted. Could anyone help? I think some hex-editing of drive should fix this.