Hard Disk Sentinel is a complete tool for checking your hard disk for problems and alert you if something is wrong on your hard disk. The screen will show you an overview of your hard disk/s, which suggests any actions need to be performed.
You can read a detailed review of this product here
The Hard Disk Sentinel also offers emergency backup of critical files (to CD/DVD, FTP, Email, transfer files to another hard disk). This will automatically save your most valuable data when your hard disk is in trouble. Hard Disk Sentinel Professional also offers a portable version which will help you to check the hard disks of any computer. This will be very useful, if you used to fix computer problems of others.
You can get a free full version license from SOS from this link