When you install Windows Server 200x, by default, it operates in remote administration mode where you get maximum of 2 active concurrent remote desktop sessions. To get more concurrent sessions, you will have to install the Terminal Server Role. Terminal Server will work because it is in a grace period. For the first 120 days after installation with Windows Server 2003, or 90 days after installation with Windows 2000, any unlicensed client can connect while the terminal server waits for you to install a licensing server. After the end of the grace period, if no licensing server is found, the terminal server will stop accepting unlicensed connections.
