You close a Widget by control-clicking it in Apple OS X or right-clicking it in Microsoft Windows and choosing Close Widget.

If you can't get the menu to appear on a particular Widget, follow these steps:

1. Close the dock.
2. Either right-click the gear icon in the Widows system tray or click the gear icon in the OS X system menu.
3. Hold down the Control key.
4. Choose the name of the Widget in the menu.