Screen grab issues

So I'm taking a screen grab of a new system we've developed and wanting to use hotspots and layers to explain what various areas of the screen do.  The screen grab looks great on the slide view, good resolution not grainy and easy to read, but when I preview it the slide looks really hazy and hard to read.  Does anyone have any pointers on how to improve this?? I'm really struggling to think of another way to present the information.  Thanks in advance