I was editing a deck for my boss when I noticed that all the slides automatically advance by itself after I pressed the F5 button. It turns out that the deck was previously set to auto advance by another author. So, here’s how to stop the PowerPoint slides from automatically moving to the next in just one step:
1. On the Transitions tab, in the Timing group, uncheck the check box for After:.

That’s it! Easy peasy, isn’t it? :)