There are few ways to do so. 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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Site Updated: October 30, 2005
http://www.pptheaven.xs3.com
PowerPoint Heaven - The Power to Animate
Contains tutorials on creating amazing animations for your PowerPoint
Presentations.
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