excessive login times while logging into windows 2000 AD DC

Tech-Archive recommends: Fix windows errors by optimizing your registry

I have 3 xp pro machines with all patches. They are all taking about a minute or longer first to initially log into the domain then once the user logs in it's another minute or so before they get the desktop. I have killed the windows firewall completely and checked my dns settings. I know there's a workaround i just don't remember what it is..:)
.