[[AgustinOrtu]]

Este es un tipico caso de herencia.. donde todos tus forms tienen que hacer lo mismo..

Podrias hacer algo asi:

Código Delphi [-]
unit UBaseForm;

interface

uses
  Forms,
  Controls;

type
  TBaseForm = class(TForm)
  public
    procedure ToggleControls(const IsEnabled: Boolean); overload; virtual;
    procedure ToggleControls(const IsEnabled: Boolean; const ControlClass: TControlClass); overload; virtual;
  end;

implementation

{ TBaseForm }

procedure TBaseForm.ToggleControls(const IsEnabled: Boolean);
var
  I: Integer;
begin
  for I := 0 to ControlCount - 1 do
    Controls[i].Enabled := IsEnabled;
end;

procedure TBaseForm.ToggleControls(const IsEnabled: Boolean; const ControlClass: TControlClass);
var
  I: Integer;
begin
  for I := 0 to ControlCount - 1 do
    if Controls[i].ClassType = ControlClass then
      Controls[i].Enabled := IsEnabled;
end;

Ejemplo de uso:

Código Delphi [-]
unit Main;

interface

uses
  UBaseForm,
  Windows,
  Messages,
  SysUtils,
  Variants,
  Classes,
  Graphics,
  Controls,
  Forms,
  Dialogs,
  StdCtrls;

type
  TForm1 = class(TBaseForm) // --> Ahora tu ancestro es TBaseForm
    Edit1: TEdit;
    Memo1: TMemo;
    btnDisable: TButton;
    btnEnable: TButton;
    Button1: TButton;
    Edit2: TEdit;
    procedure btnDisableClick(Sender: TObject);
    procedure btnEnableClick(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.btnDisableClick(Sender: TObject);
begin
  // deshabilitar todos los controles
  ToggleControls(False);

  // este boton lo dejo siempre habilitado, sino no puedo hacer mas nada
  btnEnable.Enabled := True;
end;

procedure TForm1.btnEnableClick(Sender: TObject);
begin
  // Habilitar todos los controles
  ToggleControls(True);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  // solo Edits, invertir el valor
  ToggleControls(not Edit1.Enabled, TEdit);
end;

end.