We have two servers which both authenticate users on our Win2003 server network. All of a sudden, when I try to browse to Server1 from Server2 (My Network Places, Entire Network, Microsoft Windows Network, Domain, Server1, a dialogue box appears asking for a Username and Password. This has only just started to occur. If I enter the normal administrator credentials in whatever format, I am told logon is unsuccessful. I do not get a similar request for credentials when I browse to Server2 from Server1. What is going on?