To remove the numbers from all the slides, select ‘ Apply to All ’. Additionally, you may be interested in learning how to remove the slide number from the title slide only.

They are displayed horizontally, with slide numbers starting from one, but there are features in PowerPoint that allow the user to change the slide’s size and orientation.

Launch PowerPoint 2007. Click the Windows button to open the handout presentation with the page numbers to change. Click the "View" tab. Click the "Slide Master" button on the ribbon.

Use the Slide Master view in Microsoft PowerPoint to customize the look and feel of your slides and create a consistent view for your presentation. You may wish to create multiple master slides ...

You can change the size of a slide in your PowerPoint presentation through the "Design" menu on the Windows PC, Apple MacOS, and web-based apps.