To provide a consistent user experience throughout Windows please follow their UI guidelines: Apply - will apply settings immediately, button is optional. Only incorporate this button when options are changed that can be immediately reviewed (like changing fonts/colors etc). Including this buttons usually means extra code. OK - apply changes and close Cancel - discard changes and close. Please don't reinvent the wheel, every time the user sees a different text than those above he/she need to read and think about it. You should not change their order either.