I don’t want to search for the right commands everytime I want to connect to a windows machine with RDP when I’m on a Linux machine running Ubuntu or Kubuntu that is. The best tool I know, that really does the work is rdesktop.
Install this package:
sudo apt-get install rdesktop
And then just connect with this line:
rdesktop -u user -p password -k de-ch -g 1280x1024 server
This also shows how to use a Swiss German keyboard layout, as I have searched for it many times. The thing is, that it is not an underscore, as many may think.