The Windows registry is a set of data files that helps Windows control hardware, software, user environment and Windows interface. The registry is contained in two files and in the Windows directory, as well as their backup system.da0 and user.da0. The registry database can be accessed through the programs in the Windows directory. In the past, in earlier versions of Windows (before Win95), these features were implemented by other .ini files associated with applications.
In the Windows operating system family, these two files contain all the control functions and application information of the operating system, manage computer hardware and manage desktops and applications. All drivers, fonts, settings and parameters will be saved in the .ini file, and any new program will be recorded in the .ini file. These records will be referenced in the program code. Due to limitations on file size, programmers add auxiliary .INI files to control more applications. For example, Microsoft Excel has an office file that contains options, settings, default parameters and other information related to the normal operation of Excel. In the and only the path and file name need to be pointed out.
As early as Dos and the era, most applications used ini files (initialization files) to save some configuration information, such as setting paths, environment variables, etc. And controls the characteristics and access methods of all windows and applications, it works well in a small number of users and a small number of applications. As the number and complexity of applications grows, more parameter items need to be added to the .ini file.
In this way, in a changing environment, everyone changes the .ini file after the application is installed into the system. However, no one deletes the relevant settings in the .ini file after deleting the application, so the two files will become larger and larger. Each additional content will cause system performance to become slower and slower. And every time the application upgrades, there is a problem with this: the upgrade will add more parameter items but never remove the old settings. And there is also an obvious problem, the maximum size of a .ini file is 64KB. To solve this problem, the software provider itself began to support its own .ini files and then pointed to specific ini files such as and files. In this way, multiple .ini files affect the normal access level settings of the system. If an application's .ini file conflicts with file settings, who has the higher priority?
The registry was originally designed as an application's data file related reference file, and was finally expanded to include all functions for 32-bit operating systems and applications. A registry is a set of files that control the appearance of an operating system and how it works in response to external events. These "events" range from directly accessing a hardware device to how an interface responds to a specific user to how an application runs, and so on. Because of its complex purpose and nature, the registry is designed to work specifically for 32-bit applications, with the file size being limited to approximately 40MB. Using a powerful registry database to manage system hardware facilities, software configuration and other information in a unified and centralized manner, thereby facilitating management and enhancing system stability. The most intuitive example is why different users under Windows can have their own personalized settings, such as different wallpapers and different desktops. This is done through the registry.
It can be seen that the Registry is the core "database" for Windows 9x/Me/NT/2000 operating system, hardware devices, and customer applications to run and save settings normally; it is a huge tree-like hierarchical database. It records the interrelated relationship between the software installed on the machine and each program by the user; it includes the computer's hardware configuration, including automatically configured plug-and-play devices and various existing device descriptions, status attributes, and various status information and data.
1. What does the registry do?
The registry is a data file designed for all 32-bit hardware/drivers and 32-bit applications in Windows NT and Windows 95. 16-bit drivers cannot work under Windows NT, so all devices are controlled through the registry, and these are generally controlled through the BIOS. Under Win9x, 16-bit drivers continue to operate in real mode devices, which they are used to control. 16-bit applications will work under NT or Win9x, and their programs will still reference and file to obtain information and control.
Without a registry, the operating system does not obtain the necessary information to run and control affiliated devices and applications and respond to user input correctly.
In the system, the registry is a database that records the settings and locations of 32-bit drivers. When the operating system needs to access the hardware device, it uses drivers, and even the device is a BIOS-supported device. Devices without BIOS support must be installed. This driver is independent of the operating system, but the operating system needs to know where to find them, file names, version numbers, other settings and information. Without the registry records of the device, they cannot be used.
When a user is ready to run an application, the registry provides application information to the operating system so that the application can be found, the location of the correct data file is specified, and other settings can be used.
The registry saves location information about default data and auxiliary files, menus, button bars, window status, and other options. It also saves installation information (such as date), user who installed the software, software version number and date, serial number, etc. Depending on the installation software, the information it includes is also different.
However, generally speaking, the registry controls all 32-bit applications and drivers, and the control method is based on the user and the computer, and does not depend on the application or driver. The parameter items of each registry control the functions of a user or computer functions. User features may include desktop appearance and user directory. Therefore, the computer functions are related to the installed hardware and software, so the items are all common to the user.
Some program functions have an impact on users, and sometimes they act on computers rather than set for individuals. Similarly, drivers may be specified by users, but in many cases, they are universal in computers.
2. Structural division and mutual relationship of the registry
The WINDOWS registry has six root keys, which is equivalent to a hard disk being divided into six partitions.
Enter RegEdit in the Run dialog box and click the OK button to run the Registry Editor.
The data organization structure of the registry (, ,) of the registry in Windows 98 Chinese version.
There are six root keys in the registry. These root keys are capitalized and prefixed with HKEY_; this command convention is based on symbolic variables of the keywords of the Registry function of the Win32 API.
Although in the registry, the six root keys appear to be in a juxtaposition and have nothing to do with each other. But in fact, the information stored in HKEY_CLASSES_ROOT and HKEY_CURRENT_CONFIG are all part of the information stored in HKEY_LOCAL_MACHINE, while the information stored in HKEY_CURRENT_USER is only part of the information stored in HKEY_USER.
HKEY_LOCAL_MACHINE includes all the information in HKEY_CLASSES_ROOT and HKEY_CURRENT_USER. After each system starts, the system maps the information in HKEY_CURRENT_USER so that the user can view and edit the information in it.
In fact, HKEY_LOCAL_MACHINE\SOFTWARE\Classes is HKEY_CLASSES_ROOT. For users to facilitate viewing and editing, the system specifically uses it as a root key. Similarly, HKEY_CURRENT_CONFIG\SY-STEM\Current Control is HKEY_LOCAL_MACHINE\SYSTEM\Current Control.
The user information of the default user and the currently logged-in user is saved in HKEY_USERS. HKEY_CURRENT_USER saves user information for the currently logged in user.
HKEY_DYN_DATA saves dynamic data during the system runtime, which reflects the current status of the system and is different every time it runs, even on the same machine.
According to the above analysis, the information in the registry can be divided into two categories: HKEY_LOCAL_MACHINE and HKEY_USERS. For details of these two categories, please see the introduction below.
The role of the three and six major root bonds
In the registry, all data is organized in a tree-like structure in the form of keys and subkeys, very similar to the directory structure. Each key contains a specific set of information, and the key name of each key is related to the information it contains. If this key contains subkeys, there will be a "+" symbol to the left of the folder representing this key in the registry editor window to indicate that there is more content in this folder. If this folder is opened by the user, then this "+" will become "-".
1.HKEY_USERS
This root key saves the user ID and password list stored in the local computer password list. The preconfiguration information for each user is stored in the HKEY_USERS root key. HKEY_USERS is one of the root keys accessed in a remote computer.
2.HKEY_CURRENT_USER
This root key contains the currently logged-in user information stored in the local workstation, including the user login username and temporary password (Note: this password is hidden when entered). When a user logs into Windows 98, his information is copied from the corresponding item in HKEY_USERS to HKEY_CURRENT_USER.
3.HKEY_CURRENT_CONFIG
This root key stores data that defines the current user's desktop configuration (such as monitor, etc.), the last document list (MRU) and other information about the current user's installation of Windows 98 Chinese version.
4.HKEY_CLASSES_ROOT
According to the extension of the application installed in Windows 98 Chinese version, the root key indicates the name of its file type.
When the first time installing Windows 98 Chinese version, the RTF (Rich Text format) file is associated with WordPad (WordPad), but after installing Chinese Word 6.0 in the future, Word will be automatically activated when double-clicking an RTF file. The HKEY_CLASSES_ROOT stored in the file will replace the settings item in the [Extensions] subsection in the file. It associates the application with the file extension, and it also replaces similar settings item in the file in Windows.
5.HKEY_LOCAL_MACHINE
This root key stores the hardware data of the local computer. The subkeywords under this root key are included to provide the information required by HKEY_LOCAL_MACHINE, or in a set of keys accessible in a remote computer.
Many subkeys in this root key are similar to the settings in the file.
6.HKEY_DYN_DATA
This root key stores dynamic data at runtime, and this data changes every time it is displayed, so the information under this root key is not placed in the registry.
4. Important contents of the registry
The registry is a large database registry. To analyze the database in detail, it cannot be introduced in just one or two pages. I have spent more than half a year analyzing this database structure. Only some important content is introduced below.
(I)HKEY_CLASS_ROOT
1.HKEY_CLASS_ROOT//DefaultIcon Double-click the default string on the right side of the window, delete the original "key value" in the dialog box that opens, and enter %1. After restarting, open the Windows directory in "My Computer", select "Big Icon", and then the icon of the Bmp file you see is no longer the same MSPAINT icon, but a thumbnail of each Bmp file (provided that ACDSee and other picture viewing software are not installed).
(II)HKEY_CURRENT_USER
1. Create a new string value name MenuShowDelay=0 in HKEY_CURRENT_USER\Control Panel\Desktop to increase the pop-up speed of the submenu in the "Start" menu.
2. Create a new string value name MinAnimate in HKEY_CURRENT_USER\Control Panel\Deskt-op\WindowsMeterics. The value is 1 to start the animation effect switch window, and the value is 0 to cancel the animation effect.
(III) HKEY_LOCAL_MACHINE
1.HKEY_LOCAL_MACHINE\software\microsoft\windows\currentVersion\explorer\user shell folders The path to save personal folders and favorites.
2.HKEY_LOCAL_MACHINE\system\currentControl-Set\control\keyboard Layouts Save the language used by the keyboard and various Chinese input methods.
3.HKEY_LOCAL_MACHINE\software\microsoft\windows\currentVersion\uninstall Save installed Windows application uninstall information.
4.HKEY_LOCAL_MACHINE\system\CurrentControl-Set\services\class Save the control panel - Add hardware device - Device type directory.
5.HKEY_LOCAL_MACHINE\system\Current-ControlSet\control\update Set the refresh method. The value of 00 is set to automatically refresh, and 01 is set to manually refresh [press F5 in Explorer].
6.HKEY_LOCAL_MACHINE\software\microsoft\win-dows\currentVersion\run Saves the name of the program running when the computer is started set by the control panel, and its icon is displayed on the right side of the task bar. The icon is also on the right side of the task bar when the program runs in the Start folder.
7.HKEY_LOCAL_MACHINE\software\microsoft\windows\currentVersion\Policies\Ratings Save the password (data encryption) set in "Security"\"Level Review" in IE4.0 Chinese version (data encryption). If you forget the password, delete the data in Ratings to solve the problem.
8.HKEY_LOCAL_MACHINE\software\microsoft\windows\currentVersion\explorer\desktop\nameSpace Save special icons in the desktop, such as Recycle Bin, Inbox, MS Network, etc.
(IV) HKEY_USERS
1.HKEY_USERS\.Default\software\microsoft\internet explorer\typeURLs save the URL address list information entered in the address bar of the IE4.0 browser. The document menu will be cleared.
2.HKEY_USERS\.Default\so..\mi..\wi..\current-Version\ex..\menuOrder\startMenu retains program menu sorting information.
3.HKEY_USERS\.Default\so..\microsoft\windows\current-Version\explorer\RunMRU saves the list of programs running in "Start\Run...". The document menu will be cleared.
4.HKEY_USERS\.Default\so..\microsoft\windows\current-Version\explorer\RecentDocs Save the shortcut to the fifteen recently used documents (delete to solve the problem of duplicate document names). It will be cleared when clearing the document menu.
5.HKEY_USERS\.default\software\microsoft\windows\currentVersion\applets Saves the recorded data of Windows applications.
6.HKEY_USERS\.default\software\microsoft\windows\currentVersion\runSave the name of the program running when the computer is started set by the user, and its icon is displayed on the right side of the task bar.
5. Terms related to the registry:
①. Registration: It is a tree-shaped hierarchical database. Physically, it is and two files; logically, it is the configuration data the user sees in the registry editor.
②. HKEY: "root key" or "primary key", its icon is somewhat similar to the icon of the folder in the Explorer. Windows 98 divides the registry into six parts and calls it HKEY_name, which means a handle to a certain key.
③, key: It contains additional folders and one or more values.
④, subkey: the key (subkey) that appears under a certain key (parent key).
⑤. branch: represents a specific subkey and everything it contains. A branch can start at the top of each registry, but is usually used to describe a key and all of its contents.
⑥. value entry: an ordered value with a name and a value. Each key can contain any number of value terms. Each value item consists of three parts: name, data type, and data.
★ Name: Any combination of characters, numbers, representative characters, and spaces that do not include backslashes. The same key cannot have the same name.
★ Data type: including three types: string, binary, and double-word.
String (REG_SZ): As the name implies, a string of ASCII characters. For example, "Hello World" is a string of words or phrases. In the registry, string values are generally used to represent the description of the file, the identification of the hardware, etc. Usually it consists of letters and numbers. The registry always displays strings in quotes.
Binary (REG_BINARY): For example, F03D990000BC is a binary value without a length limit. In the registry editor, the binary data is displayed in hexadecimal.
Double Word (REG_DWORD): Literally understood, it should be Double Word, double byte value. It consists of 1-8 hexadecimal data, which can be edited in hexadecimal or decimal. Such as D1234567.
★ Data: The specific value of the value item, it can occupy 64KB.
⑦. Default: Each key includes at least one value item, which is called the default value (Default), which is always a string.
In the Windows operating system family, these two files contain all the control functions and application information of the operating system, manage computer hardware and manage desktops and applications. All drivers, fonts, settings and parameters will be saved in the .ini file, and any new program will be recorded in the .ini file. These records will be referenced in the program code. Due to limitations on file size, programmers add auxiliary .INI files to control more applications. For example, Microsoft Excel has an office file that contains options, settings, default parameters and other information related to the normal operation of Excel. In the and only the path and file name need to be pointed out.
As early as Dos and the era, most applications used ini files (initialization files) to save some configuration information, such as setting paths, environment variables, etc. And controls the characteristics and access methods of all windows and applications, it works well in a small number of users and a small number of applications. As the number and complexity of applications grows, more parameter items need to be added to the .ini file.
In this way, in a changing environment, everyone changes the .ini file after the application is installed into the system. However, no one deletes the relevant settings in the .ini file after deleting the application, so the two files will become larger and larger. Each additional content will cause system performance to become slower and slower. And every time the application upgrades, there is a problem with this: the upgrade will add more parameter items but never remove the old settings. And there is also an obvious problem, the maximum size of a .ini file is 64KB. To solve this problem, the software provider itself began to support its own .ini files and then pointed to specific ini files such as and files. In this way, multiple .ini files affect the normal access level settings of the system. If an application's .ini file conflicts with file settings, who has the higher priority?
The registry was originally designed as an application's data file related reference file, and was finally expanded to include all functions for 32-bit operating systems and applications. A registry is a set of files that control the appearance of an operating system and how it works in response to external events. These "events" range from directly accessing a hardware device to how an interface responds to a specific user to how an application runs, and so on. Because of its complex purpose and nature, the registry is designed to work specifically for 32-bit applications, with the file size being limited to approximately 40MB. Using a powerful registry database to manage system hardware facilities, software configuration and other information in a unified and centralized manner, thereby facilitating management and enhancing system stability. The most intuitive example is why different users under Windows can have their own personalized settings, such as different wallpapers and different desktops. This is done through the registry.
It can be seen that the Registry is the core "database" for Windows 9x/Me/NT/2000 operating system, hardware devices, and customer applications to run and save settings normally; it is a huge tree-like hierarchical database. It records the interrelated relationship between the software installed on the machine and each program by the user; it includes the computer's hardware configuration, including automatically configured plug-and-play devices and various existing device descriptions, status attributes, and various status information and data.
1. What does the registry do?
The registry is a data file designed for all 32-bit hardware/drivers and 32-bit applications in Windows NT and Windows 95. 16-bit drivers cannot work under Windows NT, so all devices are controlled through the registry, and these are generally controlled through the BIOS. Under Win9x, 16-bit drivers continue to operate in real mode devices, which they are used to control. 16-bit applications will work under NT or Win9x, and their programs will still reference and file to obtain information and control.
Without a registry, the operating system does not obtain the necessary information to run and control affiliated devices and applications and respond to user input correctly.
In the system, the registry is a database that records the settings and locations of 32-bit drivers. When the operating system needs to access the hardware device, it uses drivers, and even the device is a BIOS-supported device. Devices without BIOS support must be installed. This driver is independent of the operating system, but the operating system needs to know where to find them, file names, version numbers, other settings and information. Without the registry records of the device, they cannot be used.
When a user is ready to run an application, the registry provides application information to the operating system so that the application can be found, the location of the correct data file is specified, and other settings can be used.
The registry saves location information about default data and auxiliary files, menus, button bars, window status, and other options. It also saves installation information (such as date), user who installed the software, software version number and date, serial number, etc. Depending on the installation software, the information it includes is also different.
However, generally speaking, the registry controls all 32-bit applications and drivers, and the control method is based on the user and the computer, and does not depend on the application or driver. The parameter items of each registry control the functions of a user or computer functions. User features may include desktop appearance and user directory. Therefore, the computer functions are related to the installed hardware and software, so the items are all common to the user.
Some program functions have an impact on users, and sometimes they act on computers rather than set for individuals. Similarly, drivers may be specified by users, but in many cases, they are universal in computers.
2. Structural division and mutual relationship of the registry
The WINDOWS registry has six root keys, which is equivalent to a hard disk being divided into six partitions.
Enter RegEdit in the Run dialog box and click the OK button to run the Registry Editor.
The data organization structure of the registry (, ,) of the registry in Windows 98 Chinese version.
There are six root keys in the registry. These root keys are capitalized and prefixed with HKEY_; this command convention is based on symbolic variables of the keywords of the Registry function of the Win32 API.
Although in the registry, the six root keys appear to be in a juxtaposition and have nothing to do with each other. But in fact, the information stored in HKEY_CLASSES_ROOT and HKEY_CURRENT_CONFIG are all part of the information stored in HKEY_LOCAL_MACHINE, while the information stored in HKEY_CURRENT_USER is only part of the information stored in HKEY_USER.
HKEY_LOCAL_MACHINE includes all the information in HKEY_CLASSES_ROOT and HKEY_CURRENT_USER. After each system starts, the system maps the information in HKEY_CURRENT_USER so that the user can view and edit the information in it.
In fact, HKEY_LOCAL_MACHINE\SOFTWARE\Classes is HKEY_CLASSES_ROOT. For users to facilitate viewing and editing, the system specifically uses it as a root key. Similarly, HKEY_CURRENT_CONFIG\SY-STEM\Current Control is HKEY_LOCAL_MACHINE\SYSTEM\Current Control.
The user information of the default user and the currently logged-in user is saved in HKEY_USERS. HKEY_CURRENT_USER saves user information for the currently logged in user.
HKEY_DYN_DATA saves dynamic data during the system runtime, which reflects the current status of the system and is different every time it runs, even on the same machine.
According to the above analysis, the information in the registry can be divided into two categories: HKEY_LOCAL_MACHINE and HKEY_USERS. For details of these two categories, please see the introduction below.
The role of the three and six major root bonds
In the registry, all data is organized in a tree-like structure in the form of keys and subkeys, very similar to the directory structure. Each key contains a specific set of information, and the key name of each key is related to the information it contains. If this key contains subkeys, there will be a "+" symbol to the left of the folder representing this key in the registry editor window to indicate that there is more content in this folder. If this folder is opened by the user, then this "+" will become "-".
1.HKEY_USERS
This root key saves the user ID and password list stored in the local computer password list. The preconfiguration information for each user is stored in the HKEY_USERS root key. HKEY_USERS is one of the root keys accessed in a remote computer.
2.HKEY_CURRENT_USER
This root key contains the currently logged-in user information stored in the local workstation, including the user login username and temporary password (Note: this password is hidden when entered). When a user logs into Windows 98, his information is copied from the corresponding item in HKEY_USERS to HKEY_CURRENT_USER.
3.HKEY_CURRENT_CONFIG
This root key stores data that defines the current user's desktop configuration (such as monitor, etc.), the last document list (MRU) and other information about the current user's installation of Windows 98 Chinese version.
4.HKEY_CLASSES_ROOT
According to the extension of the application installed in Windows 98 Chinese version, the root key indicates the name of its file type.
When the first time installing Windows 98 Chinese version, the RTF (Rich Text format) file is associated with WordPad (WordPad), but after installing Chinese Word 6.0 in the future, Word will be automatically activated when double-clicking an RTF file. The HKEY_CLASSES_ROOT stored in the file will replace the settings item in the [Extensions] subsection in the file. It associates the application with the file extension, and it also replaces similar settings item in the file in Windows.
5.HKEY_LOCAL_MACHINE
This root key stores the hardware data of the local computer. The subkeywords under this root key are included to provide the information required by HKEY_LOCAL_MACHINE, or in a set of keys accessible in a remote computer.
Many subkeys in this root key are similar to the settings in the file.
6.HKEY_DYN_DATA
This root key stores dynamic data at runtime, and this data changes every time it is displayed, so the information under this root key is not placed in the registry.
4. Important contents of the registry
The registry is a large database registry. To analyze the database in detail, it cannot be introduced in just one or two pages. I have spent more than half a year analyzing this database structure. Only some important content is introduced below.
(I)HKEY_CLASS_ROOT
1.HKEY_CLASS_ROOT//DefaultIcon Double-click the default string on the right side of the window, delete the original "key value" in the dialog box that opens, and enter %1. After restarting, open the Windows directory in "My Computer", select "Big Icon", and then the icon of the Bmp file you see is no longer the same MSPAINT icon, but a thumbnail of each Bmp file (provided that ACDSee and other picture viewing software are not installed).
(II)HKEY_CURRENT_USER
1. Create a new string value name MenuShowDelay=0 in HKEY_CURRENT_USER\Control Panel\Desktop to increase the pop-up speed of the submenu in the "Start" menu.
2. Create a new string value name MinAnimate in HKEY_CURRENT_USER\Control Panel\Deskt-op\WindowsMeterics. The value is 1 to start the animation effect switch window, and the value is 0 to cancel the animation effect.
(III) HKEY_LOCAL_MACHINE
1.HKEY_LOCAL_MACHINE\software\microsoft\windows\currentVersion\explorer\user shell folders The path to save personal folders and favorites.
2.HKEY_LOCAL_MACHINE\system\currentControl-Set\control\keyboard Layouts Save the language used by the keyboard and various Chinese input methods.
3.HKEY_LOCAL_MACHINE\software\microsoft\windows\currentVersion\uninstall Save installed Windows application uninstall information.
4.HKEY_LOCAL_MACHINE\system\CurrentControl-Set\services\class Save the control panel - Add hardware device - Device type directory.
5.HKEY_LOCAL_MACHINE\system\Current-ControlSet\control\update Set the refresh method. The value of 00 is set to automatically refresh, and 01 is set to manually refresh [press F5 in Explorer].
6.HKEY_LOCAL_MACHINE\software\microsoft\win-dows\currentVersion\run Saves the name of the program running when the computer is started set by the control panel, and its icon is displayed on the right side of the task bar. The icon is also on the right side of the task bar when the program runs in the Start folder.
7.HKEY_LOCAL_MACHINE\software\microsoft\windows\currentVersion\Policies\Ratings Save the password (data encryption) set in "Security"\"Level Review" in IE4.0 Chinese version (data encryption). If you forget the password, delete the data in Ratings to solve the problem.
8.HKEY_LOCAL_MACHINE\software\microsoft\windows\currentVersion\explorer\desktop\nameSpace Save special icons in the desktop, such as Recycle Bin, Inbox, MS Network, etc.
(IV) HKEY_USERS
1.HKEY_USERS\.Default\software\microsoft\internet explorer\typeURLs save the URL address list information entered in the address bar of the IE4.0 browser. The document menu will be cleared.
2.HKEY_USERS\.Default\so..\mi..\wi..\current-Version\ex..\menuOrder\startMenu retains program menu sorting information.
3.HKEY_USERS\.Default\so..\microsoft\windows\current-Version\explorer\RunMRU saves the list of programs running in "Start\Run...". The document menu will be cleared.
4.HKEY_USERS\.Default\so..\microsoft\windows\current-Version\explorer\RecentDocs Save the shortcut to the fifteen recently used documents (delete to solve the problem of duplicate document names). It will be cleared when clearing the document menu.
5.HKEY_USERS\.default\software\microsoft\windows\currentVersion\applets Saves the recorded data of Windows applications.
6.HKEY_USERS\.default\software\microsoft\windows\currentVersion\runSave the name of the program running when the computer is started set by the user, and its icon is displayed on the right side of the task bar.
5. Terms related to the registry:
①. Registration: It is a tree-shaped hierarchical database. Physically, it is and two files; logically, it is the configuration data the user sees in the registry editor.
②. HKEY: "root key" or "primary key", its icon is somewhat similar to the icon of the folder in the Explorer. Windows 98 divides the registry into six parts and calls it HKEY_name, which means a handle to a certain key.
③, key: It contains additional folders and one or more values.
④, subkey: the key (subkey) that appears under a certain key (parent key).
⑤. branch: represents a specific subkey and everything it contains. A branch can start at the top of each registry, but is usually used to describe a key and all of its contents.
⑥. value entry: an ordered value with a name and a value. Each key can contain any number of value terms. Each value item consists of three parts: name, data type, and data.
★ Name: Any combination of characters, numbers, representative characters, and spaces that do not include backslashes. The same key cannot have the same name.
★ Data type: including three types: string, binary, and double-word.
String (REG_SZ): As the name implies, a string of ASCII characters. For example, "Hello World" is a string of words or phrases. In the registry, string values are generally used to represent the description of the file, the identification of the hardware, etc. Usually it consists of letters and numbers. The registry always displays strings in quotes.
Binary (REG_BINARY): For example, F03D990000BC is a binary value without a length limit. In the registry editor, the binary data is displayed in hexadecimal.
Double Word (REG_DWORD): Literally understood, it should be Double Word, double byte value. It consists of 1-8 hexadecimal data, which can be edited in hexadecimal or decimal. Such as D1234567.
★ Data: The specific value of the value item, it can occupy 64KB.
⑦. Default: Each key includes at least one value item, which is called the default value (Default), which is always a string.