Forgive my ignorance...

Here at work the computers are all on a Microsoft network. Most of them are running Win98 or even 95. A few of the new ones are now Win2k. My question is:


How can I make the the Win2k computers come up with just Microsoft's login screen (Name, Pass, and Domain)? As of now only those who have a profile set up are able to logon as where the other computers (With the diff. OS`s) anyone with thier name on the server can.

I tried to word this as good as I can. I hope you all can understand what I am yacking about. Thank you for any help.