Promoting your W2K8 core to Domain Controller

To promote our W2K8 core server, we need to have an answer file for an unattented installation, since the GUI is no longer available.

Our answer file we can create on an existing DC, for example a W2K3 domain controller.
1. insert the W2K3 installation CD/DVD in your machine and extract the file ref.chm which is located in \SUPPORT\TOOLS\DEPLOY.CAB and select a destination

2. open the ref.chm file, click on Unattend.txt, then click on [DCInstall], scroll down to the example and copy this to a notepad.

3. adjust the answer file to your needs. Look for more information in the ref.chm file.
4. run adprep /forestprep on the installed DC to prepare the forest for a new DC. This can be found on the W2K8 installation DVD under Sources\ADprep. It should look something like this:

5. next is the domainprep

6. copy the file to your W2K8 core and run Dcpromo /unattend:unattendfile to start the promotion to DC

7. restart the server to apply the changes with the command shutdown /r /t 0
8. check on your original DC the Active Directory Users and Computers to see if your servre is now a domain controller

In this scenario, I've promoted my W2K8 core to a DC in an existing domain. Of course the same procedure can be applied to create a new domain or even forest.