External HDD won't show up in Disk Management or Explorer

hi there fellow uk man :) try this microsoft fix it from there site
Hardware devices are not working or are not detected in Windows go to link Hardware devices are not working or are not detected in Windows

http://support.microsoft.com/fixit/

What it fixes...

When you install a hardware device, it is not detected
Determine if your audio device is plugged in
Driver updates aren't automatically installed by Windows Update
You receive one of the following errors:
Your <Device Name> is currently disabled or turned off in Windows
Your <Device Name> has a driver problem and needs to be reinstalled
Windows has detected a problem with your <Device Name>, it is not working properly
There is no driver installed for your <Device Name>

i can understand your frustration i have had the same problem but with my main tower machine in the end i unplugged the motherboard connectors to the usb leads to the ports and that solved it windows booted and reinstalled all the usb drivers, guess that's a little of the rails for a lappy?

from op and just to make it clear there is absolutely nothing on the drive I want to keep so it doesn't matter what is lost from it!

has the drive not been for-mated with anything? no file system on it? im sure that is why windows will not see it if so. in disk management is there no sign of a drive not assigned with a drive letter etc?

at the bottom of the drive list in disc management they show up there.

"USB Device not recognized: One of the devices attached to this computer has malfunctioned and windows does not recognize it." do you get this in a pop up?

Welcome leeroy1978

Is this a new WD external HD, or have you used it in the past? If used what was on it previously? & what file system was used?