Warning The following steps will delete all items in your calendar, including holidays that are automatically added to the calendar. You can re-add or remove holidays deleted during these steps, but your other items will be unrecoverable.
1. In the Navigation Pane, click Calendar.
2. On the View menu, point to Arrange By, point to Current View, and then click By Category.
3. Click Categories: (none), and then press CTRL+A.
4. All items in the list should now be selected.
5. Press DELETE.