IPS is open but the window does not show up

Quick solution for this:

Click on IPS so it is the active app, you can tell by it having a yellow line under the icon instead of a spot (see below)

 

Press ALT + SPACE on your keyboard, you will see a dropdown appear. 

Use the ARROW keys to hover over 'Maximise' then press ENTER on your keyboard.
 

IPS should now appear, if not contact IT Support.