Good Afternoon Best,
I'm going to share a very important, sneaky trick I use all the time. I
routinely change between presentations without freezing the slides or
hiding the output from the projector. Most mosquito repellants do not
actually repel mosquitoes, they simply hide your scent from the little
buggers. (There is a connection, trust me.)
First, I use the dual monitor set-up. This means that what shows on my
laptop (PowerPoint in edit mode) is not what shows on the projector
(PowerPoint in Show mode). The projector is like an extension of my
laptop display. This link will show you more about how to set up dual
monitors ...
http://www.pptfaq.com/FAQ00231.htm
Second, I change my pretty desktop image (insipid green hill and blue sky)
to a solid black color and make sure that all my desktop icons are on the
laptop screen and not on the projector screen. This is the trick. You
see there is no difference between projecting a solid black desktop and a
solid black slide. Therefore, when I am between presentations the
projector is blank (desktop), then I start my next presentation, where I
have a beginning black slide.
The effect is a seamless presentation transfer thru a "black slide" from
one presentation to another without seeing the normal desktop. I suppose
you could change your desktop to any image you wanted to show between the
shows, I just prefer nothing.
PowerPoint is about appearance, it cares little about reality. So instead
of trying to keep the desktop from showing, just make your desktop not
look like anything. (See, I told you there was a connection.)