Cygwin

I don't see anything that looks like a telnet or ssh daemon, much less inetd. Cygwin is a Unix like shell with some Unix utilities tossed in; it is not a Unix system. There aren't even any man pages about etc/passwd.

Would Linux be better suited for your purposes?

I remember during setup there's a choice box for enabling Cygwin access for the current user or for all users. I've not tried it in both configurations to verify but it's there nonetheless.

If you have the option, try ininstalling/reinstalling and then selecting "all user" access.

I'm assuming here that people are logging on using Terminal Server or some other kind of remote access?

Hope that helps -