Finally, you need to link the looping intro to the PowerPoint presentation. Click the View tab and select Slide Master in PowerPoint 2007 or go to the View menu in PowerPoint 2003, point to Master and click on Slide Master. Add an Action Button to all slide masters in use. In PowerPoint 2007, select the Shapes drop-down on the Home tab and select an Action Button. In PowerPoint 2003, select AutoShapes from the Drawing toolbar. Point to Action Buttons and select the button you wish to use.

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When you place the Action Button onto the slide master, the Action Settings dialog will open. In the Hyperlink To field, select Other PowerPoint Presentation. Find the meeting presentation to which you want to link the looping introduction slide show and click OK. Select the first slide of the main presentation in the Hyperlink to Slide box and click OK. Click OK to apply the link. Repeat with any other slide masters being used in the looping intro PowerPoint presentation. This will add a hyperlinked button to each slide in the presentation. Save the slide show one final time.
Before your presentation, start the looping intro slide show. Whenever you are ready to begin, click the Action Button on the current slide. PowerPoint will immediately switch to your main presentation.
For more helpful PowerPoint articles, check out the Bright Hub Collection of PowerPoint Tips, User Guides, and Tutorials.