After having the same problems that most of you are having with my WD 1TB external hard drive, I uninstalled the unknown device and started over. I disconnected all usb devices and attempted to plug in my usb from the external hd to one of the two rear usb ports. did not work. I once again uninstalled the unknown device and attempted to plug it in to one of the two usb ports on the front of my machine and it worked. I am assuming it is a power issue through the usb. Once I get it to load then plug in all other usb devices it works fine but if i try to restart or attempt to plug in my external hdd while other usb devices are connected it will not work properly and will be recognized as an unknown device.
Just FYI hope this helps someone.
PT
