Start Flash Professional. Click "Open" in the "File" menu and navigate to the FLA file that you want to convert to a widget and open it.
Click "Publish Settings" in the "File" menu. Now click the "Formats" tab in the dialog box. Click the "Windows Projector" check box to create a Windows desktop widget. Click the "Macintosh Projector" check box to create a Macintosh desktop widget.
Click "Publish" in the dialog box to create and save the projector file (the widget file). Open the file directory where your FLA file is. Observe that a new file has been created that has the same name as your FLA file, but with an "exe" extension if you selected a Windows widget or an "app" extension if you selected a Macintosh widget.
Click the newly created Window or Macintosh widget file to play the widget. Move your widget file to your desktop so that you can use the widget from there.