To "square-up" the part to the screen, from the Graphics Modes toolbar, select the 2D Rotate Mode icon , and then right-click on a CAD element. PC-DMIS rotates the drawing so that the selected element is parallel to the closest screen axis (vertical or horizontal).
You can square-up the drawing to the closest X, Y, or Z axis at any time, even if you don't have the Rotate dialog box open. Click twice on the Graphic Display window with your mouse wheel button.