Mudar a senha do Windows 2012 via remote desktop - Change the password through the terminal service
Press WindowsKey+R (or get the Run box open) – then type OSK (It will open ‘on-screen-keyboard in your remote-remote session). Or open on-screen keyboard in a different way.
Then press on your physical keyboard (not on that on screen!!) ctrl and alt keys. Using your mouse tick DEL key on ‘On-screen-keyboard’.