When the Depo© window opens first time, it fills the whole screen. Depo© is then in its Maximized position.
You can reduce it by clicking on the button in the upper right corner of the screen, just to the left of the X in the red rectangle. This button switches the Depo© window from reduced to maximized position by clicking again on the same button.
In the reduced position, it is possible to resize your Depo© window and move it.
Resize it, move the mouse to a corner of the Depo© window. When the mouse cursor becomes a double arrow, press and hold mouse button, move the mouse to the desired new size, and then release the button.
Press and hold the mouse button in the middle of the title bar, move the window to where you want, and then release the button to save your new position.
Find more information about working with Windows on Microsoft website by clicking this link.