Marking a task as complete is the best part of creating tasks in the first place. Just like using a pen or pencil to cross an item off of a paper To-Do list, marking a task as complete has a certain sense of accomplishment that comes with it.
And, Outlook continues to track a task, even after it has been marked as complete – it’s a little reminder of all you have accomplished.
Marking a Task Complete Using the Standard Toolbar
Open an existing task
Choose the Mark Complete command on the Task Standard toolbar
Marking a Task Complete Using the Shortcut Menu
Select the task you want to mark as complete
Right-click the selected task
Choose Mark Complete from the Shortcut menu