Closing windows and projects
To close a window onto a project, where views are displayed in tabs, click the tab's 
button.
To close a window onto a project, where views are displayed in distinct window s rather than tabs, make the window active then click its 
button.
Closing a window onto a project does not close the project, unless the window you are closing is the only window open onto the project. To close a project, click the File tab, then click Close.