How to Turn a Kindle From a Horizontal to a Vertical Positionby C. Taylor
Properly formatted e-books automatically wrap text in the Kindle's screen, so you don't need to scroll left or right to view content. However, large images cannot wrap and many e-books are not formatted to fit the Kindle's default vertical orientation, so the default vertical orientation may have been changed to accommodate such files. To change the orientation back to vertical, you need to access the Kindle's font settings.
Press the "Text" key, indicated by the letters "Aa," on your Kindle Keyboard. If your Kindle doesn't have an integrated keyboard, press the "Menu" button and select "Change Font Size" with the five-way controller.
Highlight "Screen Rotation" by pressing down on the five-way controller.
Highlight the first or third graphical option and press the center of the five-way controller to select it. Both options use vertical orientation, but the first places the keyboard and buttons on the bottom, while the other places them on the top.