Getting to know all about Windows Registry
I was going through the Book “Windows 7 UNLEASHED , SAMS publication” that sneaked my attraction on very interesting chapter which was all about the registry. So i thought it would be better to rip out some content for our blog readers.
The Registry is a central repository Windows uses to store anything and everything that applies to the configuration of your system.
This includes all the following:
- Information about all the hardware installed on your computer
- The resources those devices use
- A list of the device drivers that Windows 7 loads at startup
- Settings that Windows 7 uses internally
- File type data that associates a particular type of file with a specific application
- Backgrounds, color schemes, and other interface customization settings
- Other customization settings for things such as the Start menu and the task bar
- Internet and network connections and passwords
- Settings for Windows 7 applications such as Windows Explorer and Internet Explorer
- Settings and customization options for many third-party applications
To launch the Registry Editor, select Start, type regedit into the Search box, and then press Enter. When the User Account Control dialog box shows up, enter your credentials to continue.
http://winspark.net/wp-content/uploa...4/registry.png
Understanding Registry settings
If the left side of the Registry Editor window is analogous to Explorer’s Folders pane, theright side is analogous to Explorer’s Contents pane. In this case, the right side of theRegistry Editor window displays the settings contained in each key (so I’ll call it theSettings pane). The Settings pane is divided into three columns:
- Name – This column tells you the name of each setting in the currently selected key(analogous to a filename in Explorer).
- Type – This column tells you the datatype of the setting. There are six possible datatypes :
REG_SZ – This is a string value.
REG_MULTI_SZ – This is a series of strings.
REG_EXPAND_SZ – This is a string value that contains an environment variable name that gets “expanded” into the value of that variable.
For example,the %SystemRoot% environment variable holds the folder in which Windows 7 was installed. So,if you see a Registry setting with the value %SystemRoot%\System32\, and Windows 7 is installed in C:\Windows, the setting’s expanded value is C:\Windows\System32\.
REG_DWORD - This is a double word value: a 32-bit hexadecimal value arranged as eight digits.
For example,11 hex is 17 decimal,so this number would be represented in DWORD form as 0×00000011 (17). (Why “double word”? A 32-bit value represents four bytes of data,and because a word in programming circles is defined as two bytes,a four-byte value is a double word.)
REG_QWORD – This is a quadruple word value: a 64-bit hexadecimal value arranged as 16 digits. Note that leading zeros are suppressed for the high 8 digits. Therefore,11 hex appears as 0×00000011 (17),and 100000000 hex appears as 0×1000000000(4294967296).
REG_BINARY – This value is a series of hexadecimal digits.
- Data—This column displays the value of each setting.
Getting know the Registry’s’ Root Keys :
HKEY_CLASSES_ROOT – usually abbreviated as HKCR—contains data related to file extensions and their associated programs, the objects that exist in the Windows 7 system, as well as applications and their automation information. There are also keys related to shortcuts and other interface features.
HKEY_CURRENT_USER – usually abbreviated as HKCU—contains data that applies to the user that’s currently logged on. It contains user-specific settings for Control Panel options, network connections, applications, and more. Note that if a user has group policies set on his account, his settings are stored in the HKEY_USERS\sid subkey (where sid is the user’s security ID). When that user logs on, these settings are copied to HKEY_CURRENT_USER. For all other users, HKEY_CURRENT_USER is built from the user’s profile file, ntuser.dat located in %UserProfile%).
HKEY_LOCAL_MACHINE (HKLM) containsnon-user-specific configuration data for your system’s hardware and applications.
HKEY_USERS (HKU) contains settings that are similar to those in HKEY_CURRENT_USER. HKEY_USERS is used to store the settings for users with group policies defined, as well as the default settings (in the .DEFAULT subkey) which get mapped to a new user’s profile.
HKEY_CURRENT_CONFIG (HKCC) contains settings for the current hardware profile. If your machine uses only one hardware profile, HKEY_CURRENT_CONFIG is an alias for HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001. If your machine uses multiple hardware profiles, HKEY_CURRENT_CONFIG is an alias for HKEY_LOCAL_MACHINE\SYSTEM\ControlSetnnn, where nnn is the numeric identifier of the current hardware profile.
From : Getting to know all about Windows Registry | winspark.net
