Starting and Exiting the Data Editor
  To start or exit the Data Editor:
Start by double-clicking a data file
   You can start by double-clicking a data file in Windows Explorer if you have associated Data Editor to the data file type beforehand using the Tools > Folder Options > File Types dialog box.
Exit
  To exit Data Editor, select Exit from the File menu.  If data has been changed, a message is displayed asking whether to save the changes.
  Data Editor can also be exited as follows:
Mouse Click the close icon X in the upper right corner of the Data Editor window.
Keyboard Press Alt + F4