Can’t get on W2k server but can on NT

Last year, we installed an 80211b wireless with no problems. All servers at that time were NT. We recently removed several NT servers and added W2k servers.

I had to create a local user account on several wireless laptops as software we are using is so old that people have to have admin rights to use it. So, they log into the computer instead of the domain.

When doing this, and navigating to the servers, one can see all servers on the network: NT and W2k. When attempting to log into the NT servers, no problems. The user name box pops up and asks for name and password. Once given , entry is allowed. When trying to log into the W2k servers, the log in box appears but one can’t log in. If the proper information is entered, the log in box keeps popping back up. Help!