I think what you are asking is how to setup an Active Directory domain. the short answer is to run DCPROMO from a command prompt. however, there are some additional steps you need to take before you implement a domain.
Is this your only server? Is there an existing domain? Or do you just have a workgroup setup at this time?
I have quite a bit of tutorials on Windows Server 2008 you can refer to. In addition, if this is a for a small office network, refer to this guide for some guidance on the IP design and services configuration.
yah the DCPROMO IS nw prompted a box.....and i checked the create a new domain in an existing forest....and also checked the ....create a new domain tree root intead of new child domain ...i hope am correct...
1) Setting up the first domain controller (DC) in a new forest/domain - Run this option when this is the first DC
2) Create a new child domain in an existing Forest - this option is used when you already have a forest and root domain set up and you need a new instance of a domain within the same forest as a child or new tree. Too many details to conver in this post/thread.
3) Add a new DC to an existing domain-- this is a common option when you already have a domain setup and you simply need to add another DC to this domain.