2. Step 01: Create a new presentation in PowerPoint and insert a blank slide or insert a blank slide in an existing presentation. Step 02: Insert a text box and type the number '1' or '01' or ‘00:01' depending on how many digits you want your counter to display. Center the text, change the font style, and increase the font to a large size. Step 03: ChooseAnimation tab > Transition to This Slide (PowerPoint 2007) or Slide Show > Slide Transition (PowerPoint 2003)to apply a slide transition and set the advance to the desired interval (1 second, 1 minute, etc.)
3. Step 04: Choose View > Slide Sorter (both versions) and click the formatted timer slide. Right-click on slide and left-click on Copy then right-click again to Paste an identical slide. Repeat as many times as you want to create the sequential slides for the countdown timer.
4. Step 05: For each of the consecutive slides, edit the numbers.