Win2003 Network logon problem

From: DonD (dierking_at_cox.net)
Date: 09/06/04 

Date: Sun, 05 Sep 2004 21:21:33 -0700

I have a server running Windows 2003, and several workstations running
Windowx XP. Last Monday, the workstations suddenly could not access
the server without an id/password. Once given, everything is great
until a reboot requires a repeat. What setting in 2K3 should I reset
to stop this authentication?