Most of the computer user's nowadays do experience a problem in which most cases involve the disruption of the system from booting to window enviroment without them haven't backed up their data. If you are experiencing such a problem, then you are reading the right topic because you will be taught how to recover your files.
Before i commence,i would assume that you know what HARDDRIVE means and what it's being use for.

Things that disrupt your system from booting
[1]Virus
[2]Corruption of harddisk
[3]One of the booting files may be missing/corrupted . Etc.

How to recover data/files [br/] [**]Through the use of harddisk: [**]
All you need to do is just to remove the harddisk(of the crashed system) then plug it to anoder system using PCI (Peripheral Component Interconnect) or you can also connect it using usb cable.Then you can transfer your data & files from the plugged harddisk to the new harddisk on your other system.
Thou, you can also use some recovery software but the most effective way is to make transfer between the two harddisk.
Source:http://www.nigerianblog.net/forum2_theme_112148371.xhtml?tema=1

Meaning of harddisk(HDD)
It is a magnetic disk with large storage space capacity, usually found in technology device e.g computer. For storing data & files permanently and retrieves when needed.
It is a non-volatile memory i.e The data on it is safe even if there is power failure.