How to mark a To Do as complete? March 30, 2015 15:27 Please start in the Agenda Section. After To-Do is completed click the check box To unselect a To-Do activity click on the selected check box Related articles What is included in iCal Export? What is the difference between Act! 365 and Act! Growth Suite Starter? How to Add a note to an activity How to clear completed To-Do's How do I record an Activity from a Contact?