Once the software opens, on the Top Menu bar, Select MANUAL (M) and depress Goniometer control. This opens the Manual Goniometer Control Window as shown:
Select the OMEGA tab, Toggle the Init. button as in the image below. This lets the system Initialize OMEGA; it finds as set ω to 45 degrees and displays that value in the window. Do this before you mount your sample or put the collimator into place, so as not to drive the stage / sample into the collimator.