So In Windows Server 2008, there are roles such as AD Domain Services, DHCP, DNS, the roles services pertaining to roles such as AD Certificate Services, DFS, and finally there are optional features such as .NET Framework Services, Network Load Balancine (NLB), etc. With the exception of the Active Directory Domain Services role, you install server roles and features by using the ocsetup command. The syntax for ocsetup is the same for roles and features. The command is case sensitive, and you need to know the correct capitalization for a server role or feature, you can get that by running oclist command.

For instance, the following command installs Windows Server Backup, which is a feature

start /w ocsetup WindowsServerBackup

Using the /w switch indicates when ocsetup has finished installing the new role of feature. It also stops user from initiating another command while it’s running.

You can also find out what is already installed by running following oclist syntax

oclist | find "installed"