MV
This is the only software i know that may do what you want
ADingOD Display Saver revives normal screen saver during PowerPoint screen
shows (it may work for other apps too). This hidden utility allows most
screensavers to work as expected while Powerpoint is running in full-screen
mode. This is helpful for kiosk developers who want to leave their
"presentations" running 24-hours per day while preventing screen burn-in
(especially over-night).
http://www.adingod.com/kiosk.html
Cheers
TAJ Simmons
microsoft powerpoint mvp
awesome - powerpoint backgrounds,
http://www.awesomebackgrounds.com
free powerpoint templates, tutorials, hints, tips and more...