see if you get any where with this. plug in the external unit. if it reacts anything like what i've seen and shows an driver error in the device manager. try disabling the usb2 root hub or via enchanced host controller. the drive should then install the driver and be assigned a drive letter in explorer on it's own without rebooting.
why, i have no idea. whether that helps you or not is an unknown also. might give you some where to look.
ud
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