This Guide should help you to install Roles and Features on Windows Server 2008 R2 per shell or on a Windows Server 2008 R2 Core Server.
Under Windows Server 2008 you could install Roles and Features with the command OCSETUP. Since we use Windows Server 2008 R2 Microsoft used the tool called DISM (Deployment Image Servicing and Management tool).
For checking availible Server roles type:
Dism /online /get-features /format:table
To enable a Feature or a Role, in this case the DNS Server Role, you just type:
Dism /online /enable-feature /featurename:DNS-Server-Core-Role