Notice the ' Compact view' on the screenshot? If you click on it, Windows Live Mail will only show icons on the left. If you are showing the reading pane at the bottom, both it and the email folder listing will use that extra space. As soon as you do, the email you have currently opened will use all that extra width.
Then, click on the Calendar pane button, as shown on the screenshot. To hide it (or resume showing it), select the View tab in the ribbon. Unfortunately, there's no dedicated keyboard shortcut to toggle the mini-calendar's visibility. Collapse the preview calendar on the right
