Go in to Windows XP Disk management to make a partition on it and format it. It might have to be activated also (via right click), but I'm not sure of that.
Aren't there some instruction coming with the disk?
One partition, formatted NTFS, should be OK.
any help would be greately appreciated but i just recently boughbt a brand new WD 160Gb Passport external hardrive and every time i plug it in no matter what computer it will not show up. It just says unknown device but i cant access it or anything. Can anyone shed some light on this?