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

private

    procedure WMSysCommand(var Msg: TWMSysCommand); message WM_SYSCOMMAND;

   {...}
 implementation


 procedure TForm1.WMSysCommand(var Msg: TWMSysCommand);
 begin
   if ((Msg.CmdType and $FFF0) = SC_MOVE) or
     ((Msg.CmdType and $FFF0) = SC_SIZE) then
   begin
     Msg.Result := 0;
     Exit;
   end;
   inherited;
 end;