I have Windows Advance server 2000 running on my P3, but what made you want to put it on your laptop?
Anyway Windows Server OS's dont have the similar drivers and applications running as XP or Vista..... but you can try plugging the Ex Hard drive and then reboot the laptop to get it recognized.
Does the Ex Harddrive have 2 Usb that plug in without AC power or does it have just 1 usb and additional power that comes from the outlet?