To remove a task list,

1. Hover your mouse over the task list name and click Remove.

tasklist-remove

2. Click OK if you are sure you want to remove the task list. Or, click cancel to go back to the tasks page.

tasklist-remove-confirmation

If you make a mistake and want to recover your task list, you can recover your task list within 30 days from Removed Items.

pod-settings-removeditems