Hai sir,
I had some problem, I have the server 2003 connecting with 12 PC through the lan

With domain, 11 pcs are working and join the domain .but one PC I tried to same method what I did , but I get some error messeage the administrator restict something,it not join the domain please help me over all xpsp2

What user account are you using to join the computers to the domain? If the user account does not have Domain Administrator privilages then it is restricted to adding a maximum of 10 computers to the domain. You can delegate permission for the user to add Computer Objects to the domain.