function RegisterEvents(data : Pointer) : Integer;
begin
  with Form1 do begin
    DBOspitiEvent.Registered := true;
  end;
end; //<-- AFTER THIS, APPLICATION IS BLOCKED (for a while)

procedure TForm1.Button2Click(Sender: TObject);
var
  ThreadId : Cardinal;
  ThreadHandle : Integer;
begin
  ThreadHandle := BeginThread(nil,0,@RegistraEventi,nil,0,ThreadId);
  if ThreadHandle = 0
    then ShowMessage('Error');
end;