reading on desktop with ADE 4.5

Had to start using this version, as previous (2.0) stopped working for me. Finally have things downloading properly, but went to read EPUB library book on desktop and can only access a portion of the first page of each chapter. I can't view an entire page at a time, and there's no scroll bar on right. Using arrows, scroll bar at bottom, or pg up/pg down buttons moves me to the previous or next chapter. How do I either change the format to show an entire page at a time or to scroll down to read the rest of a page?