How to use Registry for saving and restoring form state and position?

unit Main;

interface

uses Windows, SysUtils, ... , Registry;

type
  TMainForm = class(TForm)
  ...
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  ...
  private
    procedure ReadSettings;
    procedure WriteSettings;
  public
    FIniFile: TRegIniFile;
  end;

var
  MainForm: TMainForm;

const
  Section = 'MainWindow';

implementation

procedure TMainForm.ReadSettings;
begin
  with FIniFile do
  begin
    with MainForm do
    begin
      Left := ReadInteger(Section, 'Left', Left);
      Top := ReadInteger(Section, 'Top', Top);
      Height := ReadInteger(Section, 'Height', Height);
      Width := ReadInteger(Section, 'Width', Width);
      if ReadBool(Section, 'Maximized', False) = True then
        WindowState := wsMaximized;
    end;
  end;
end;

procedure TMainForm.WriteSettings;
begin
  with FIniFile do
  begin
    with MainForm do
    begin
      if WindowState = wsMaximized then
      begin
        WriteBool(Section, 'Maximized', True);
      end else
      begin
        WriteBool(Section, 'Maximized', False);
        WriteInteger(Section, 'Left', Left);
        WriteInteger(Section, 'Top', Top);
        WriteInteger(Section, 'Height', Height);
        WriteInteger(Section, 'Width', Width);
      end;
    end;
  end;
end;

procedure TMainForm.FormCreate(Sender: TObject);
begin
  FIniFile := TRegIniFile.Create('Software\MyCompany\MySoftware\Version');
  ReadSettings;
end;

procedure TMainForm.FormDestroy(Sender: TObject);
begin
  WriteSettings;
  FIniFile.Free;
end;