If you are running ASIAIR v1.3, there should be two buttons above the large round button on the right of the main window. The topmost button shows the current mode, and the one below it shows the current bin configuration.
Currently, you can select one of four modes: Focus, PA, Preview and Autorun. Click on the mode button and ASIAIR shows the mode menu.
Click on PA in the menu, and the mode button should now show "PA," and you are in the Polar Alignment window.
Chen