Under older versions of windows you had to double click the top right area as the 'close' window action.
which should have read top LEFT
The other option is to single click that top left box and select the CLOSE option.
Remember that when setting Newport Stock codes to use all 5 characters (maybe underscores to pad out shorter codes to 5 characters). Help within Newport is via F1 key.
Shift-F4 on the maintenance screen is another useful key sequence to remember that brings up the Portfolio Control adjustment screen.