Sit back for a minute and think about how much it would suck if your hard drive failed tomorrow without warning. How much of your data do you have backed up and how much would you lose. Fortunately, in many cases there are some warning signs and preventative measures.

Performance Suffers

One of the earliest warning signs will be frequent computer freezes or lock ups. It may seem like the computer is really slow since mouse movement and keyboard response will be off. Problems During Boot You may also notice that your computer locks up or gets stuck during the boot-up of your operating system. You may restart and everything works fine but it happens again from time to time.

S.M.A.R.T

Any hard drive built in recent times will include something called S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology). This allows for the monitoring and tracking of most problems that may arise with your hard drive. It isn't fool proof but if enabled from within the BIOS can usually warn of impending failures.

Manufacturer's tools

One of the best ways to check for possible hard drive problems is to use the free tools made available to you by the manufacturer of your hard drive. Find out who makes your hard drive, go to their website and download the appropriate diagnostic tools. Some common HDD manufactures are: Western Digital, Seagate, Toshiba

Backups

Of course it isn't a bad idea to make backups of your most important files from time to time, because even if you check your HD regularly for problems it still could fail unexpectedly. Also consider storing important files in the same folder, this makes backing up much easier.