If you are using PowerPoint 2002/XP and above,
you can set password to protect your presentation from modifying.
Go to Tools > Options > Security. Set your password there.
If you are using PowerPoint 2000 and below, this feature isn't supported.
You can though, embed your presentation into MS Word or Excel.
Check this out for more information:
"Password protect a presentation" http://www.rdpslides.com/pptfaq/FAQ00038.htm
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Shawn Toh (tohlz)
Microsoft Most Valuable Professional (MVP PowerPoint)
Site Updated: June 08, 2006
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