Not quite sure i understand the problem from the info so far.

a] what exactly do you mean in the first sentence "ubuntu 8.10
printer". You have a printer that'll work on ubu 8.10 and want it to
work on win2k? In ubu when it is installed [assuming printer is
connected and switched on] it will setup the printer automatically
finding correct drivers. So why do you want to set up a printer for a
lower grade OS like windoze when ubu does it perfectly!

b] you have two XP machines and you added the printer drivers from a
disk or downloaded them. Works ok? good

c] laptop win2k older software so doesn't have drivers already
installed. Go to manufacturers website and they'll probably have the
driver there for download - win2k version. I'd be surprised if the
drivers were different from win2k and xp. Some are - some aren't. I
have a scanner that works on one driver file for win98 to xp.