When you make a connection to another computer using your Remote Desktop Connection (RDP) program, the computer name or IP address you entered is saved in the program so you can easily refer to it later. If you want to change this domain, you can do so quite easily by just opening the software.
Start up your computer, log in and click the "Start" button. Click "Run" and type "mstsc" into the Run window (without quotes). Press the "Enter" key, and the Remote Desktop Connection window will open.
Use your mouse to highlight the domain currently in the Remote Desktop Connection window, then press the "Delete" or "Backspace" key.
Type in your new domain name and click the "Connect" button to continue with the connection.