Sigh... let's see if I can get this right...
...okay. In NT operating systems, access to objects is governed by access control lists. Anyone who wishes to access an object must provide a username and password, the OS will look up the user account associated with that username and password, compare that to the list of who's allowed to access the object, and decide whether or not to grant access to the object.
Windows 9x is kinda being forced into this paradigm that it wasn't really designed for. Win9x doesn't really have user accounts.
First, on the W2K machine, go to the printer properties, go to permissions, and give Everyone permissions to print. That *should* take care of it. Note that "authenticated users" is different from "everyone."
Otherwise, you'll have to log on to Win9x with a username that also exists on the W2K box, and present the password for the account on the W2K box, and give permissions to that account on the W2K to print to the printer.
Ideal solution: ditch 9x operating systems (95, 98, Me) and create an NT domain, so you have one user account database that's shared among all computers on the network. I do realize that's not always a viable solution.