i need a timer in powerpoint that the audience can't see.

[Lori]

Is there a feature (not rehearse timings) where it will start a
stopwatch/count down of time left that only is seen on the presenter machine
and not on projected image? For example you have 1 hour and 30 minutes to
present, a stopwatch will tell you how much time you have left.

Thanks,

 

[John Fallon]

You might want to take a look here:
http://www.rdpslides.com/pptfaq/FAQ00081.htm
Hope this helps!!!