Yes, Sandeep is correct. All you basically need is Active Directory. Making a domain is simply taking a computer which is connected as a workgroup, opening a brower, typing in http://connect, and following the prompts. The server will set up a user, email account if you have exchange, a users folder, etc. Once you reboot, you will be on a domain.
It's a good idea to use a different computer name, so Reception becomes Reception01. While you may have already been using DHCP on the server, make sure you do now.
