I have two caddied HDD's each with two partitions. HDD-1; C: & D:, HDD-2; E: & F: HDD-2 is a mirror backup of HDD-1. Having made the copy, it boots OK with both drives available but if I try and boot with HDD-1 (C: & D only, start up hangs. I try and reset but still hangs. If I switch power on to HDD-2 (E: & F kicks into life and powers up to desktop. Perhaps I'm not performing procedure correctly so help appreciated on resolving.