I would like to password protect my external hd only, please can you suggest software that is simple to use, inexpensive or free that I can download straight on to the hd. Been looking at folder lock, lockngo, portable fpe usb and some others, would appreciate your advice, thanks
TrueCrypt and FreeOFTE are both free, I use them both (for different things - the latter has a PDA compatible version). Possibly not the easiest software to use, but IIRC they both have "Wizards" that will walk you through the process.
I'd empty the disc and encrypt the whole thing, then fill it up again with your data.