The little box in that features information in the background of your screen can be removed by following these steps.
Step 1: Select System.
Step 2: Select System Options.
Step 3: Click the Remote Effects Box from On to Off.
At this point if you are running in full screen mode you will need to switch you Windowed mode and then back to full screen mode.
You can do this by using the keyboard command Alt-Enter. You may have to do this one or twice in order for the box to disappear.