.When you open a diagram, it is read into your computer’s memory. As you work on the diagram, the changes you make are temporary. To make the changes permanent, you must save them to disk. If a diagram has unsaved changes, an asterisk (*) is appended to the diagram name in the title bar.
To save a block diagram
•From the toolbar, choose .
•Choose File > Save (CTRL+S).
If the diagram contains one or more embedded diagrams, any changes you make to those diagrams are not saved until you use the File > Save Embedded Files command.