PowerPoint will always fit the height of the slide to the height of the
display/the width of the slide to the width of the display (so far as it can w/o
distorting the slide's proportions).
If your monitor is landscape, that's what PPT will fit it to.
If an external controller rotates the output, PPT won't know about it.
You may need to (painful!) create a landscape presentation with everything
rotated onto it so that when you lie down it looks portrait.
Or export all the images in the presentation you have, then reimport them and
rotate them onto a landscape presentation.
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Steve Rindsberg, PPT MVP
PPT FAQ: www.pptfaq.com
PPTools: www.pptools.com
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