Requirements:

Forest (initial domain controller or root domain controller)
On member server or stand-alone machine.
Specify the server’s DNS
.
Start>run>dcpromo>next>next>next
>Domain Controller for a new domain.
Select Domain tree in an existing forest.
Specify the root domain’s admin’s name & pwd
Next> specify the new domain name>next
>net bios name>next>database > next
>sysvol>next>DNS next>permission compatible
>next>restore mode pwd>next