A machine we have at work uses Windows XP (as all the other machines). It has a 1 Gig onboard ethernet controller. It takes forever to log into the domain (about 10 minutes). With the same account it would take very little time to log into another machine. I tested to see if it was the NIC card... and was able to copy a 250 mb file in about 10 seconds. One symptom that I can note is that when I try to log in through this machine the login screen grays out for about 20-30 seconds before it proceeds into the next logging in messages. Our AD is Win 2003 Server.