With Office 2010 the circle ‘office button’ in the upper left of all applications is replaced with a simple ‘File’ button that opens the Backstage.
Click the ‘File’ button the Backstage takes over the full application window.
The Backstage is a great consolidation of tools and options. But I have seen many users struggle with how to close, or go back to their slides. If you click the ‘EXIT’ button, it closes the presentation vs. closing the Backstage.
The way to go back to the slides/close the Backstage, click on the ‘FILE’ button again or any of the tabs – home, insert, design, etc.
– Troy @ TLC