when i restart my computer with the external HD on, my system hangs at the manufacturer screen. i have to power off computer manually, power off HD and then start up computer without HD switched on. system now boots up normal, then i have to switch HD back on. does anyone have a suggestion as to how i can solve this boot up problem? i have in BIOS the systems internal HD as first boot up device but to no avail. hope someone can enlighten me.