User Logins

I am changing from a Workgroup environment to a W2K3 Server enviroment. I have XP Pro, Windows 2000 and Windows 98 workstations. My problem is that when I log a machine onto the Domain for the first time it treats the login like a newly created user. I loose all or that individuals settings and have to spend a lot of time trying to copy profiles, which I might add does not work on all machines for some reason.

Does anyone have an easy way to handle this.