click start control panel administration tools computer management device manager look through all of your devices if you see a yellow question mark?or exclamation mark ! or red xright click to reinstall drivers or
if you can see your usb but its not workingports(com&lpt)right click update driver
if this fails to fix the problem
check usb leads for secure dust free seating
sometimes the wires inside the cable will be damaged due to bending or stretching or placing heavy equipment upon the cable
just replace the cable of the hard disk, when you plugged the external disk drive you got that windows could recognize the USB device change the cable everything should work fine again,
check the USB leads that attach to the motherboard usually red-white-green-black make sure they are securely seated and have no dust build up on them dust will cause static and a lot of unforeseen problems hope this helps
3 questions posted
Usually answered in minutes!