Oh del, why is the universe always throwing stuff at you? Hope you've got some time to prepare your move. Perhaps you should collect some of the termites and place them around the place next time a potential buyer comes.
Catch-Up, have you tried connecting the external drive (USB probably) to another USB port in your computer? Or do you know someone on whose computer you might try it? Does the external drive appear to have power (LEDs working, thing making any sound at all)? If you're into experimenting and your computer allows you to burn CDs, you could download a Linux live CD (for example Knoppix
, boot it and see if the drive appears there. If it does appear there, your Windows is at fault. If not, it's a hardware issue.
However, I'd say that either one (or several) of your computer's USB ports is broken or the drive does not get power. It's hard to tell without physical access to the machine.