calendar data loss

This tag covers discussions about calendar data loss in Windows, particularly when using the built-in Calendar app. A common issue involves the Calendar app being replaced or overridden by Microsoft 365 or Outlook, causing existing appointments and entries to disappear. Users often report that their calendar appears blank after such a change, even if they never intended to use Outlook or Microsoft 365. The tag includes troubleshooting steps for recovering lost calendar data and understanding why the switch occurred, especially for Windows 10 users who may have installed extended updates. Topics also include preventing future data loss and managing default calendar applications.