How can I trust a new domain - win 2000 adv. server sites of domain

ken

from 2 weeks ago i was having a domain controller for my network that contains 12 PCs , then i creat a new chield domain that trusted automatically to the original domain controller . after that the domain controller becames failed and dropped down that because the hard disks was failed . i replace these hard disks and reinstalled win2000 adv. server again .
Now i cannt to trust the chield domain to the original domain controller . How can i make it ?
According to i can ping to chiled domain server correctly , has a win2000 adv. server also