What is Windows Registry ?

Windows Registry is a database used to store information that is necessary to configure the system for one or more users, applications and hardware devices and it keeps record of the settings of all the Software installed in Computer including Operating System.

Windows Registry contains five Hives and hives contain Keys and Sub keys and their respective Values.


For Registry Editing:

Start > Run > Regedit


HKEY_CURRENT_USER: Contains the configuration information for the user who is currently logged on. The user’s folders, screen colors, and Control Panel settings are stored here.


HKEY_USERS: Contains all the actively loaded user profiles on the computer.


HKEY_CURRENT_USER is a subkey of HKEY_USERS.


HKEY_LOCAL_MACHINE: Contains configuration information particular to the computer(for any user).


HKEY_CURRENT_CONFIG: Contains information about the hardware profile that is used by the local computer at system startup.


HKEY_CLASSES_ROOT: The information that is stored here makes sure that the correct program opens when you open a file by using Windows Explorer.



Types of Keys

Binary Value (REG_BINARY): Raw binary data. Most hardware component information is stored as binary data and is displayed in Registry Editor in hexadecimal format


DWORD Value (REG_DWORD): Data represented by a number that is 4 bytes long (a 32-bit integer).Can also contain binary, hexadecimal, or decimal format


Expandable String Value (REG_EXPAND_SZ): A variable-length data string. This data type includes variables that are resolved when a program or service uses the data


String Value (REG_SZ): A fixed-length text string


Multi-String Value (REG_MULTI_SZ): Values that contain lists or multiple values in a form that people can read are generally this type.