When I intend to capture a full-screen video using Camtasia, I usually do three things to prepare my Windows 7 desktop:
First, I record in widescreen aspect ratio (16:9) since that is the standard used by YouTube, my production destination of choice. It is also the standard for most of the computers on our campus. Therefore I set my screen resolution to 1280 x 720, what they call 720p video. In older versions of Camtasia, and on slower systems I have seen Camtasia throw an error message when capturing or editing video at higher resolutions. And in any event, you certainly wouldn’t want to display a screen larger than this, so I pick it as the optimal resolution.
Second, I set the screen background to a solid color, for two reasons: a) to reduce the load on my graphics card; and b) to eliminate the distractions of a colorful, scenic screen.
Third, I set the taskbar in Windows 7 to auto-hide so that it will disappear during full-screen recording. If not, your audience will be spending time trying to figure out what programs you run from the taskbar rather than paying attention to your message. The downside of doing this is that you have to remember not to stray your cursor to the bottom of your screen unless you actually want the taskbar to pop up.
As they say, a picture is worth a thousand, and a video worth a million, so here is my YouTube video demonstrating these three steps.