The hard drive is the component that stores digital data on your computer. It is where all your files and photographs are located. Unfortunately, because it is so integral and thus does a lot of work, the hard drive is likely to crash one day and prevent access to your data. When it does fail it may start emitting a clicking sound, delay your start up, or prevent your computer from booting up. There are, however, techniques to recover data from a crashed hard drive.
Data Retrieval Software
There are many different software packages available that claim to be able to retrieve data from crashed hard drives. Some are free and available to download while other require payment and may necessitate purchase of a disk. Across Internet forums there are widely differing reviews concerning the efficacy of these products, so it may be advisable to start by trying a free version.
Placing your hard drive into an external case and plugging it into another computer may enable access to your data. The external case allows the drive to communicate with another computer thus bypassing any internal problems in the original computer that may have caused the corruption of the hard drive. Simply place the drive in the case, attach the case via a USB cable and try to open the drive via the start up menu.
Temporary Operating System
You can try using a Linux Live operating system for your computer. You ill need access to another computer with Internet access to download and burn a Linux Live CD (Damn Small Linux or Puppy Linux are good ones to try). Insert the burned CD into your computer and when you boot it up go to the start up logistics page (usually accessed by pressing F2 or Esc). Select CD as your start up system, save your option and exit. When your computer boots it will use the Linux system and should recognize the hard drive. Copy your files to an external storage device such as memory stick.
It sounds unlikely, but putting your hard drive into the freezer for a few hours may help it to work long enough for you to extract your data. The idea is that cooling it in this way constricts the components for a short time before it "thaws" so that they work together. Place the drive in a zip-loc bag and place in the freezer for six hours. Take out and plug into your computer, preferably via an external case.
If none of the above techniques are successful, the last recourse is to a professional data retrieval service. Most computer stores have a technical service department that will assess your hard drive and attempt data retrieval. It is, however, likely to be expensive.