Hard Drive failure is a PC user's worst nightmare - if you haven't got anything backed up, there's very little you can do to recover any of the data.
If your hard drive supports SMART monitoring however, there is a way to constantly check the health of your hard drive to make sure you don't run the risk of disaster. Drive Health basically keeps you informed of any potentially dangerous hard drive degradations or irregular performance issues that could cause a failure. Drive Health carries out a series of attribute tests and diagnostics without really slowing down your PC. CPU usage is minimal and it can even be run simply as an NT service. It's estimated that mechanical failures account for around 60 percent of drive failures which is a significant number because they can be avoidable with some warning of impending doom usually indicated by the drive skipping or grinding while in operation. If you are suspicious that your drive is operating irregularly, or have noticed some random problems then Drive Health may help you diagnose the problem.
It doesn't support all hard drives but Drive Health is what all diagnostic tools should be - discreet, thorough and effective.