RTO Pro requires a screen area of at lease 1024x768 pixels. If you start RTO Pro and your screen size is smaller than the required size the Windows Display Properties dialog box will be started automatically. This will look similar to the picture below.
The section that is circled in red is what you need to change, you slide the slide bar to the right until it says 1024x768 pixels or greater, then click "OK". (In the picture below the slide bar has a blue X on it)
Note: After you change this setting you may need to change the settings on your monitor to make it display properly (the controls that are on the monitor itself, vertical size, horizontal size, position, etc.).
To bring up the Windows Display Properties dialog box you can also double click on "Display" from the Windows Control Panel.