rebuild primary domain controller

Hi guys & gals & professionals

Any body can tell me if a domain have only one primary domain controller and if that domain controller crashed,then is there any way to rebuild the primary domain controller?(If I have NTDS.DIT backup file of crashed primary domain controller)

If any body know plzzzzzzzzz mail me that particular doc or link which is very very useful for me.

plzzzzzzzzzzzzzzzzzzzz…..
my e mail id:ap9am@hotmail.com