Windows Calendar is the built-in calendar application in Windows Vista.
Lightweight and easy to use, Windows Calendar doesn't include a ton of features, but does provide a decent calendar application for regular users. There's an integrated task list as well as the ability to view internet calendars.
- Subscribe to Internet Calendars
Removing Windows Calendar
There's no built-in method to uninstall Windows Calendar. It can, however, be disabled through a registry hack.