In a small shop with an NT4 PDC, I've been trying to connect some new machines.  The clients are Windows 7 professional, 64-bit.  Trying to map a network drive from the PDC fails (invalid username/password), so does trying to join the domain.  I've tried user-pass, user/domain-pass, etc., no luck. Finally, I went over to the NT4 server, and took a look in the event log.  No reports of any failed logins at all.  Now I'm confused. I made sure that the Win7 clients have the client for Microsoft networks, and that they have file sharing enabled.  Just for fun, I even tried with their firewalls turned off.  No luck. Is there something I'm missing here?