make sure both computers has the correct hardware setup for a home network / LAN. i've done so for connection to my ADSL router modem by connecting both computers to the modem.
both your win2k & winxp must set to a same workgroup name.
restart your computers after setting so.
now your win2k must b able to access share folders on winxp.
on winxp, however, when you are trying to click on win2k computer, it prompts you for username/password.
so, go to win2k, setup the same user account as per your winxp current login (or the account that you'd like to access win2k's share folders).
now, make sure you are using the account on winxp, you should've no problem to access win2k share folders now.
append: oops, sorry didn't know that this is an old thread, i was browsing for help before i posted & i only got this idea after several tries on the machines.