Do Windows XP and Windows 2000 Professional have built-in Terminal Services CALs?
No, Microsoft`s desktop operating system products (including Windows XP and Windows 2000 Professional) do not have a “built-in” Terminal Services CAL. Rather, the Windows 2000 server issues machines running Windows 2000/XP Professional with a free Terminal Services CAL from its built-in pool (and its use is permitted under the Windows 2000 Server EULA). Windows XP Professional is a successor to Windows 2000 Professional, and as a result does not need a Terminal Services CAL to access a Windows 2000 Server running Terminal Services. However, Windows XP Home Edition is not a successor to Windows 2000 Professional (rather, it is a successor to Windows Millennium Edition) and therefore does require a Terminal Services CAL in order to access Windows 2000 Terminal Services.