Don't try to save a presentation directly to a CD. PowerPoint isn't designed to
write to CD's. Save it to your hard drive
and then use your CD burning software to move it to a blank CD.
This may sound stupid - but I make the mistake all the
time - I put and reference the wrong CD drive, ie., the
one I try to write to is not writable - insure you have a
writable CD drive. Then, utilize CD burning software on
your computer, if yu have a writable CD, to "copy" or
write your presentation to CD.