I have used the following without success. The active workbook closes, indeed, but the excel window remains open.
Application.ActiveWindow.Close SaveChanges:
Sub button2_click()
'
' Button2_Click Macro
'
' Keyboard Shortcut: Ctrl+Shift+Q
'
ActiveSheet.Shapes("Button 2").Select
Selection.Characters.Text = "Logout"
ActiveSheet.Shapes("Button 2").Select
Selection.OnAction = "Button2_Click"
ActiveWorkbook.Saved = True
ActiveWorkbook.Save
Application.Quit
End Sub