Yes you can. The first thing to do is to stop using your computer. The best way of recovering your deleted files is to remove the hard disk and fit it via the USB port to another computer which has a free program like PC Inspector File Recovery on it. If you can't or won't do this then your chances of recovering all of your data is reduced but the data may still be recoverable if you install the recovery program on the hard disk which has your data on it. Are you feeling lucky?