I've added a second Sata internal hard drive to my desktop and although the computer can 'see' both drives via Device Manager, and both appear to be working ok (no yellow ? logo's present), I can only see one drive via Windows Explorer. The problem appears to have started after I used Partion Magic to change partition sizes on one of the drives. I'm guessing it's a mapping problem, but I'm unsure as to how to correct this problem. Can anyone help at all.