Introduction to Windows Registry

Six key roots in the registry, all data is organized in a tree structure with keys and sub-keys, very similar to the directory structure. Each key contains a specific set of information, and the key names for each key are related to the information it contains. If the key contains a subkey, the left side of the folder that represents the key in the Registry Editor window will have a "+" sign to indicate that there is more content in the folder. If the folder is opened by the user, then this "+" will become "-". 1:hkey_users The primary root key holds the list of user IDs and passwords stored in the local computer's password list. The pre-configuration information for each user is stored in the  hkey_users root key. HKEY_USERS is one of the root keys that are accessed in a remote computer. 2:hkey_current_user The primary root key contains the current logged-on user information that resides in the local workstation: includes the user login user name and the staged password (note: This password is hidden when entered). When a user logs on to the Windows 98 operating system, their information is copied from the corresponding entry in the HKEY_USERS to HKEY_CURRENT_USER. 3:hkey_current_config The primary root key holds data that defines the current user's desktop configuration (such as displays, etc.), the last Used document list (MRU), and other information about the installation of the Chinese version of the current user's Windows 98 operating system. 4:hkey_classes_root The primary root key contains all the OLE information and document types registered, which are copied from the HKEY_LOCAL_MACHINE\Software\Classes map. Depending on the extension of the application installed in the English version of the Windows 98 operating system, the root key indicates the name of its file type. 5:hkey_local_machine The primary root key holds the local computer hardware data, the subkey under this root key is included in the SYSTEM.DAT to provide the information required by the HKEY_LOCAL_MACHINE, or in a set of keys accessible on the remote computer. Many of the subkeys in the root key are similar to those set in the System.ini file. 6:hkey_dyn_data The primary root key registry entry exists only in Windows 95, Windows 98, Windows 98 SE, Windows Me or more, and the primary key stores the system's dynamic data at run time. This data is changed each time it is displayed, so the information under this root key is not placed in the registry. A special registry key can have subkeys, just as a folder can have subfolders. Each key can have multiple values associated with it and store information. Each value holds a portion of the information, and each part can be obtained or updated when needed. EachThe subkeys hold information specific to the application, such as color settings, screen location and size, or recognizable file extensions. The maximum depth of the registry key value is 15. This is a limitation of the Windows CE operating system. Note that the information stored in the registry is easily used by other applications and users, so do not use it to store secure data (such as passwords) or critical application information. Type binary (binary) of "key value data item" in the registry, the binary is not of the length limit, and can be any length of a byte. In the Registry Editor, binary data is displayed in 16 binary, such as: "Customcolors" key value is a binary data, double-click the key value name, the "Edit Binary Value" dialog box, we can switch between binary and hexadecimal. The DWORD Value (DWORD) DWORD value is a 32-bit (4-byte, double-word) Length value. In Registry Editor, as with binary values, you will find that the system displays the DWORD value in 16 binary, and when editing a DWORD value, you can choose to enter it in binary, decimal, or hexadecimal mode. String value (SZ) in the registry, the string value is typically used to represent the description of the file, the identity of the hardware, and so on. Usually it consists of letters and numbers. The content in the text entry field is a key value, which is a type of string value. A key value item data can be formed by the key value name and the key value, which is equivalent to the set line under the subsections in the Win.ini, System.ini file. In fact, you use Registry Editor to export these key-value item data in exactly the same way as the settings in the. ini file. The keys of the   registry data type registry contain data in a variety of different formats. Data types can be categorized as: Common data types--windows the operating system comes with Registry Editor--regedit.exe, RegEdt32.exe, and most other third-party registry editing tools that are supported and capable of editing data types. The Windows NT kernel has various operating system-specific data types--regedt32 and several other registry tools that support and can edit data types. Special data types specific to component/application-Registry tools support these data types, but there is a limit to the program. The user can only edit it as a binary number. In fact, registry tools can also edit unsupported data types, including those displayed as Reg_unknown types. But editing can only be done in binary mode, which requires the user to have a good understanding of the format of the data object. For those who need to manually modify the registry, it is important to understand each data type and the storage format of each type of data.

Introduction to the Windows Registry