Did you purchase your machine from a local dealer? If so they should be able to help you.
Does yours have Artista Software that you run? There is where you change from MM to inches on my 440.
Bringing this back to the top for you, bkd147. I have a Janome, so I don't know what your Bernina wording would be, but on the touch screen there is an icon for the equivalent of "setup" on the tv remote. I can set thread pallette, inches or mm, stitch speed, light, auto-sleep, etc. I'm pretty sure Jerrilyn has a Bernina, maybe she will see this and be able to answer you. Did you look at your manual? Ask your dealer? Best of luck to you!! Marji