Оформил: DeeCo
Автор: http://www.swissdelphicenter.ch

uses
   ComObj, ActiveX;

 function CreateGuid: string;
 var
   ID: TGUID;
 begin
   Result := '';
   if CoCreateGuid(ID) = S_OK then
     Result := GUIDToString(ID);
 end;

 procedure TForm1.Button1Click(Sender: TObject);
 begin
   Edit1.Text := CreateGuid;
   // or: Edit1.Text := CreateClassID 
end;