Should you desire to change the session window (how big the screen is) I have listed directions below.
Please note, sometimes simply pressing CNTL + ALT + Pause|Break on your keyboard will Auto-Fit the remote session.
Download the Icons attached to your Desktop. If you already have the icons, you don't need them again. Right click on one of them and hit Edit.
Click the Display Tab
Change the slider to match the resolution of your desktop or laptop. If you do not know the resolution of your computer, right click on the Desktop and hit Screen Resolution.
A window will appear and tell you if what your screen resolution is.