When you run it in MAS 90 mode it should launch the login screen and you can then type in your user name. I wonder if you are getting that because they have Unified Logon setup. Did they even have Unified Logon back then? I think this was only available in MAS 200 in the 3.71 version and not MAS 90, so that may be the issue here. There is an INI file somewhere that you can edit to turn off NT Login, but I can't remember off the top of my head which one.