Salvar/restaurar o tamanho e posição de Form’s no Delphi

 Crie uma nova Unit conforme abaixo: 

unit uFormFunc;

interface
uses Forms, IniFiles, SysUtils, Messages, Windows;



procedure tbLoadFormStatus(Form: TForm; const Section: string);
procedure tbSaveFormStatus(Form: TForm; const Section: string);

implementation

procedure tbSaveFormStatus(Form: TForm; const Section: string);
var
  Ini: TIniFile;
  Maximized: boolean;
begin
  Ini := TIniFile.Create(ChangeFileExt(
    ExtractFileName(ParamStr(0)),'.INI'));
  try
    Maximized := Form.WindowState = wsMaximized;
    Ini.WriteBool(Section, 'Maximized', Maximized);
    if not Maximized then begin
      Ini.WriteInteger(Section, 'Left', Form.Left);
      Ini.WriteInteger(Section, 'Top', Form.Top);
      Ini.WriteInteger(Section, 'Width', Form.Width);
      Ini.WriteInteger(Section, 'Height', Form.Height);
    end;
  finally
    Ini.Free;
  end;
end;

procedure tbLoadFormStatus(Form: TForm; const Section: string);
var
  Ini: TIniFile;
  Maximized: boolean;
begin
  Maximized := false; { Evita msg do compilador }
  Ini := TIniFile.Create(ChangeFileExt(
    ExtractFileName(ParamStr(0)),'.INI'));
  try
    Maximized := Ini.ReadBool(Section, 'Maximized', Maximized);
    Form.Left := Ini.ReadInteger(Section, 'Left', Form.Left);
    Form.Top := Ini.ReadInteger(Section, 'Top', Form.Top);
    Form.Width := Ini.ReadInteger(Section, 'Width', Form.Width);
    Form.Height := Ini.ReadInteger(Section, 'Height', Form.Height);
    if Maximized then
      Form.Perform(WM_SIZE, SIZE_MAXIMIZED, 0);
      { A propriedade WindowState apresenta Bug.
        Por isto usei a mensagem WM_SIZE }
  finally
    Ini.Free;
  end;
end;

end.


  Em cada formulário que deseja salvar/restaurar:
  - Inclua na seção uses: uFormFunc
  - No evento OnShow digite: 
    tbLoadFormStatus(Self, Self.Name);
  - No evento OnClose digite:
    tbSaveFormStatus(Self, Self.Name);