Windows Vista Registry Structure HKEY_LOCAL_MACHINE REG_DWORD REG

Windows Vista's Registry Structure

It really does help troubleshooting if you understand the registry's structure. In particular, knowledge of the layout will prevent you navigating to the wrong section. My foibles include thrashing around in the HKEY_LOCAL_MACHINE section, when I should be tracing a setting in the HKEY_USERS hive. Another of my common blunders is creating a REG_DWORD instead of a REG_SZ, or vice versa. While I still occasionally make these and other mistakes, thanks to my experience of the registry structure, I can soon correct my errors.

Topics for Vista's Registry Structure

Types of Registry Folders

The layout of the Vista registry is remarkably similar to that found in NT 4.0, Windows 2000 and XP.

Registry Folder or Hive

What it contains

HKEY_LOCAL_MACHINE

Holds configuration settings for the computer (no matter which user logs on).
Can be abbreviated to 'HKLM'.

HKEY_USERS

Contains all the actively loaded user profiles on the computer. More often than not, you would configure the subfolder under HKEY_CURRENT_USER which corresponded to a particular user. Most common of all, you would edit a value under HKEY_CURRENT_USER.

Subsets of Main Hives

HKEY_CLASSES_ROOT

HKCR is an alias of HKEY_LOCAL_MACHINE\Software. These settings ensure that the correct program opens when you launch Windows Explorer.

This information is stored under both the HKEY_LOCAL_MACHINE and HKEY_CURRENT_USER keys. The HKEY_LOCAL_MACHINE\Software\Classes key contains default settings that can apply to all users on the local computer. The HKEY_CURRENT_USER\Software\Classes key contains settings that override the default settings and apply only to the interactive user.

HKEY_CURRENT_CONFIG

Contains settings which control the hardware profile that is used by the computer at startup.

HKEY_CURRENT_USER

Contains the settings for the user who is currently logged on. HKCU for short

Registry Data Types

Data type

Common Name

Description

REG_DWORD

DWORD Value

Data represented by a 32-bit integer (4 bytes long).

REG_SZ

String Value

A fixed-length text string. However, REG_SZ can also hold numbers.

The above REG_SZ and REG_DWORD are by far the most common registry types. However, I include the other types below for completeness.

REG_MULTI_SZ

Multi-String Value

A multiple string. A data type capable of holding more than one value. Separate each entry by spaces, commas, or other marks.

REG_EXPAND_SZ

Expandable String Value

A variable-length data string. This data type is by system variables.

REG_BINARY

Binary Value

Raw binary data. Displayed in hexadecimal format.

REG_QWORD

QWORD Value

Data represented by a number that is a 64-bit integer. This data is displayed in a Binary Value.

REG_RESOURCE_LIST

Binary Value

A series of nested arrays, designed to store a resource list.

REG_RESOURCE_REQUIREMENTS_LIST

Binary Value

A series of nested arrays that are designed to store a device driver's list of possible hardware resources.

REG_FULL_RESOURCE_DESCRIPTOR

Binary Value

A series of nested arrays that is designed to store a resource list that is used by a physical hardware device.

REG_LINK

Link

A Unicode string naming a symbolic link.

REG_NONE

None

Data with no particular type. This data is written to the registry by the system or applications and is displayed in Registry Editor in hexadecimal format.

Registry Files and Their Physical Location

Registry Hive

Supporting files in \Windows\System32\Config

HKEY_LOCAL_MACHINE\SAM

Sam, Sam.log, Sam.sav

HKEY_LOCAL_MACHINE\Security

Security, Security.log, Security.sav

HKEY_LOCAL_MACHINE\Software

Software, Software.log, Software.sav

HKEY_LOCAL_MACHINE\System

System, System.alt, System.log, System.sav

HKEY_CURRENT_CONFIG

System, System.alt, System.log, System.sav, Ntuser.dat, Ntuser.dat.log

HKEY_USERS\DEFAULT

Default, Default.log, Default.sav

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Windows Vista's Registry Structure

Windows Vista's Registry Structure

Topics for Vista's Registry Structure

Types of Registry Folders

Registry Data Types

Registry Files and Their Physical Location

Configuring Windows Vista Topics:

Vista Tools and Extras

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