Windows XP has a built in Remote Desktop client to connect to Windows servers running Terminal Services. If you use Windows 2000 you can download the Remote Desktop client on Microsoft's site.

Once the Remote Desktop client is installed go to Start->(All) Programs->Accessories->Communications->Remote Desktop Connection . Once opened enter your Cortex server's IP Address and click Connect. This will replace your system's desktop with the desktop of your dedicated server. Log in with your Administrator username and password to get started. Remember to disconnect or log off when you're done using the server.

There is also a Remote Desktop client for the Macintosh available for download on the Microsoft site.