[rastafarey]

Esto funciona perfecto no veo cual es el problema.

Aqui tienes un codigo ejemplo

Solo pruebalo

Código Delphi [-]
unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    BitBtn1: TBitBtn;
    Edit1: TEdit;
    procedure BitBtn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

Uses ShellApi;

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
  Edit1.Text := 'http://www.clubdelphi.com/foros/forumdisplay.php?f=19';
  ShellExecute(Handle,nil,PChar(Edit1.Text),'','',SW_SHOWNORMAL)
end;

end.