How do i add users to a domain on windows server 2003

Hi , I have installed the server 2003 SP2 package, completed. I have created my domain and activated. I can access the domain as an administrator from all 5 computers on the network. On active directory I have created users on the domain and set the password to reset after first logon. From the Windows Xp pc I logon with the new user, it prompts me to change my password, i do and when I change it it says that the domain is not yet available. Please help are there rights that i have to give the users as I have just created them.