Is it possible to create a secure zone on a USB drive? I don't want it on an internal drive because if the drive fails, then my backup is useless. By storing the backup on the external USB drive, if my internal drive fails, I still have a chance of recovering my system. When I use the "Manage Acronis Secure Zone" wizard, my USB drive is listed but selecting it as the drive for the secure zone is not possible as it is greyed out (disabled). Why is it greyed out and if this is deliberately done by Acronis, why?