Select the "Annotation" icon from the ribbon toolbar:
Click, hold and drag to create a box where you want to Zoom in on the image.
When the Zoom Box is selected, you will see the white "Grab Handle" dots on the area around which you are zooming. The Zoomed box will have a single yellow grab handle in the center. You can use these handles to move and/or resize the individual windows.
There is a sample video of the steps above on our YouTube channel here: https://www.youtube.com/watch?v=vyuI_SLzFN0