Steps to protect a presentation by setting up a password on it:

• A password protects a presentation from being opened or modified by others.
• Select File > Info to add password protection to a file.
• Select Encrypt with Password > Protect Presentation.
• Enter the password you'd like to use in the Password box. Choose OK.
• PowerPoint asks you to confirm your password by typing it in again.
• Save the file to confirm that the password is applied.
• PowerPoint does not allow password security for ODP (Open Document Presentation) files.

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