This answer is more of a work-around. The first button defined in the dialog receives this highlighting. In my case I have seven pages of buttons. To resolve having one of the selections highlighted I reordered the button definitions. Since I have buttons to select the page to be displayed, I added those buttons first. Now when the dialog is displayed all the buttons are displayed without highlight except the page button. Since I initialize with page 1 viewed and that is the first button defined, all looks proper. I don't know the reason for this all but it does seem related to the default button for the dialog. I tested with various messages like DM_SETDEFID, BM_SETSTYLE and DM_SETDEFID but was never able to rid myself of the highlight. Another way might be to first create an unused button and make it invisible. For now, I have probably spent too much of your time fussing with this. I have the result I want in the app even if I lack understanding of the reason behind it.