Unzip the files and change the the "Current Directory" in MATLAB. Afterwards you can use the function "maximize.m". This function does the same as pressing the "maximize" button on the top right of the window. When you press the "maximize" button after using this function, the figure window will restore to its previous size.
The function is specific to Mircosoft Windows.

Examples:

maximize the current figure
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maximize;

maximize the current figure
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maximize(gcf);

maximize the specified figure
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h = figure;
maximize(h);

maximize the application window
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maximize(0);

maximize more than one figure
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h(1) = figure;
h(2) = figure;
maximize(h);

maximize all figures
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maximize('all');

maximize a GUI in the OpeningFcn
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% --- Executes just before untitled is made visible.
function untitled_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject handle to figure
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% varargin command line arguments to untitled (see VARARGIN)

% Choose default command line output for untitled
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes untitled wait for user response (see UIRESUME)
% uiwait(handles.figure1);

% maximize the GUI
set(hObject,'Visible','on');
maximize(hObject);