Full screen records your entire desktop and you can change the Display Settings to change the resolution from Display Properties (Windows 2000/XP) and Display Settings (Windows Vista).
Display Properties in Windows XP
Display Settings in Windows Vista

You can also change the display resolution from the wizard easily. Select the display resolution and color quality from the drop down menu and click Change Now to change the settings.
We recommend you to change the color quality to 16 bits when you record since you will get a much smaller file size. Please note that the most commonly used display settings are 1024X768 (16 bit) and 800X600 (16 bit). 1024X768 is the most common screen resolution and you don’t want to make the video bigger than your viewer’s screen resolution because then the full recorded screen will not be able to be viewed.