To adjust this windows issue follow these steps.
To move the window hover over the Nutritionist Pro Purple Icon and then when a smaller pop up comes up right click on it and select Move. Next hit an arrow key that will bind your window to the mouse. Then move the mouse and bring the window to the screen.
On newer versions of Windows, you will need to hold the shift key when right clicking the taskbar. You will know if this is needed if your version of Windows normally displays a preview of the window when you right click the NPR button on the taskbar.
Sometimes when you update a machine a graphics card can do that so see this picture to help you bring the main screen back.