I routinely update Firefox in the classroom on freshly re-imaged computers. The image is very old and has a very old version of Firefox. The machines are supposed to be identical and so is the image. I have noticed that when I run the installer on each machine, ''sometimes'' there is a checkbox about resetting everything, and I have to manually check it and continue. However, sometimes there isn’t. Otherwise my setup procedure is identical. Is there a startup option to always bypass the checkbox?