After a task list is completed, you can clear the completion status, due dates, and alerts for all tasks within a selected task list. This allows tasks to be reused for a future planning period.
Alerts are enabled only when task lists contains due dates. Clearing task lists disables alerts by clearing the check boxes for due dates. It does not delete the dates.
To clear task lists:
Open the Manage Task Lists page.
See Managing Task Lists.
Select the folder with the task list to clear, select the task list, and then click Edit.
From the Clear drop-down list, select an option:
Completion Status: Clears completion status only
Due Dates and Alerts: Clears any alerts that are enabled, based on the due date set for the task
Both: Clears completion status, due dates, and alerts.