I create my slide using illustrator (from CS2 to CS5) and when I save the file in pdf format, a red line is being created around the rectangle border of the silde.
I don't know how it was generated and what to do to remove it.
I need help please.
Is it vector or raster artwork?
A few images might reveal something, one preferably being a screenshot with the artwork selected, maybe along with an opened Leyer.
You might just be seeing a non-printing trim box, In Acrobat, go to preferences> General> Page Display> Show art, trim and bleed boxes (uncheck).