This describes how to use your RPi as a remote terminal to a Windows machine. It assumes that the Widows machine has Remote Desktop installed and enabled.
Firstly, install the remote desktop package on you RPi:
sudo app-get rdesktop
The above command needs checking. The RPi website was down when I tried to check.
Haveing installed the remote desktop on the RPi the remote machine is accessed by something such as the example below
rdesktop -x:l -r sound:remote hostname
hostname can be replaced by an IP address
For a list of options. The example above indicates that the remote machine is on a local LAN, i.e. -x:l gives maximum bandwidth and that the sound is to be left on the remote machine.