The Windows registry is a vital database that is used to store configuration information for Microsoft Windows. The registry is a focal storage point for all personal computer configuration files and data which also takes important software and hardware into account.

Everyday information such as the addition or removal of new devices, the installation of software and modification option for programs are stored in the registry as well as more complicated data. The registry database even retains key information about things like user preferences that have a marked effect on the way a user works with his computer.

This information is continually circulated through the Windows operating system during use to ensure your computer behaves in the way you expect it to.
This information is stored in the registry as a structured and hierarchical table of keys, sub-keys and values. If this information is incorrectly changed, the results may cause serious damage to your computer and Microsoft recommend that the registry is backed up before any editing takes place.

It is important to note that the registry is not located to a single file, but is actually place around a computer in several different files. Depending on the system configuration of the computer you are using, the registry can be found in any of the locations that follow:

C:Documents and SettingsUser Name (On Windows 2000 and XP).
C:WindowsSystem32Config (On Windows 2000 and XP).
C:Windows (On Windows 95, 98 and ME).
C:WindowsProfiles (On Windows 95, 98 and ME).

Registry data can be found in registry hives that are usually located in the following files:

System.dat, User.dat andPolicy.pol (On Windows 95, 98 and ME).
Security, System.alt, Default, Sam, Software, System, NTuser.dat and other files. (On Windows 2000, NT and XP).

It is important to note that the registry files cannot be backed up with Windows NT, 200, XP or Vista because they remain locked while the Windows operating system is still in use. Because of this, the ‘System Restore’ feature must be used for registry back-up.

Another alternative is to use the registry editor to export either complete or partial files of the registry and back them up using a popular form of back-up utility software. This way, any errors in editing can be restored using the backed-up file.
To use the registry editor, use the following method:

Click Start > Run.

In the open box, type the word ‘regedit’ then click ‘OK’.
Locate and highlight the root sub-key that contains the junior sub-keys you wish to back-up.

Click File > Export.

Using the ‘Save In’ box, choose a location for the .reg file to be saved, name the file and click ‘Save’.

Whilst backing up is a studious process when using Windows 2000, NT and XP, the process when using older versions of Windows is essentially automatic although back-up can be performed manually if required.