You can show and hide the Contents pane using the Show and Hide buttons on the toolbar.
When the left pane is hidden the help viewer looks like it does below. Notice the Show button on the left of the toolbar. Click the Show button and you will see the window as it appears above.
When the left pane is showing the help viewer looks as it does below. Notice the Hide button on the left of the toolbar. Click the Hide button and you will see the window as it appears above.
