For environments that don’t already have an AD RMS server in place (legacy Windows Server 2003 RMS will work as well), a new Windows Server 2008 R2 AD RMS environment is required. Note that the RMS server requires a separate server from the SharePoint farm servers, and will also require a database for the AD RMS database. In many cases, the AD RMS database server will be the same server as the SharePoint database server.
To install and configure AD RMS on a server, first install Windows Server 2008 R2, (Standard, Enterprise, or Datacenter will work) with the default installation options and then add it to the domain. Log in as an account with local admin access to the box and perform the following steps to install AD RMS: