Networking XP laptop and Win2K PC

I can’t connect to my PC running Win2K with my
laptop that’s running XP. I’m using a wireless
connection, connecting through a Linksys router
from my laptop. I have internet access and can
find and see the PC, but when I connect to it, I
get a login screen, but it won’t accept any usernames
and passwords that I have setup on the PC. I can
connect to the laptop from the PC and access the
folders and files I have setup to share.
I’ve ran out of settings to look at, does anyone
have a specific idea of what the problem could be?

Thanks, Dwain