If you are not familiar with Active Directory and infrastructure setting up a DC might seem like a daunting process, but it isn’t really. Let me break it down for you.
The process for Serve 2008 R2 and 2012 is similar, the pictures just change. If you have 2012 you should be able to use this guide as long as you bear in mind that you might have to look for where the buttons are.
Step 1. Log into the server of you choice and start Server Manager
Step 2. Go to Server Roles and Add Roles