PowerPoint allows you to modify the master slide. This is useful when you are re-formatting more than half your slides. You can modify the master slide and have PowerPoint format the slides for you. You can also add to the Slide master elements that you want to appear on each slide including: company's name and logo, URL, etc.

1. Choose View then Master to display the Slide Master
   
   
2. Click in the boxes to edit the styles and double click to format the AutoShape