In the PowerPoint window, click the File menu.
The PowerPoint window closes, and the taskbar button for the program no longer appears on the Windows taskbar.
You can close PowerPoint when you finish working on a presentation. Closing the application frees up system memory. If you leave too many programs open at a time, your computer's processing power slows down.
If you have not saved your work, PowerPoint prompts you to do so before closing the program window. Click Yes to save the file or click No to exit the program without saving your work.
Using the Close Button
You can also click the Close button (x) located in the upper-right corner of the program window to quickly close PowerPoint.