Registry knowledge: HKEY_LOCAL_MACHINE root key detailed (a)

        The HKEY_LOCAL_MACHIN root key stores the settings used to control the system and software. Since these settings are set for users who use Windows systems, it is not related to specific users. It is a common configuration information, and you only need to know one. HKEY_LOCAL_MACHINE includes the following five subkeys: HARDWARE subkey: This subkey stores some information about hypertext terminals, math coprocessors, and serial ports. The HARDWARE subkey includes two subkeys DEVICEMAP (for storing device images) and DESCRIPTION (for storing system information). The hierarchy of the DEVICEMAP subkey is as follows: HKEY_LOCAL_MACHINE\\HARDWAREHKEY_LOCAL_MACHINE\\HARDWARE\\DEVICEMAPHKEY_LOCAL_MACHINE\\HARDWARE\\DEVICEMAP\\SERIALCOMM includes the following settings under the HKEY_LOCAL_MACHINE\\HARDWARE\\DEVICEMAP\\SERIALCOMM branch: *COM1=COM1: Specify the COM1 port. *COM2=COM2: Specify the COM2 port. The hierarchy of the DESCRIPTION subkey is as follows: HKEY_LOCAL_MACHINE\\HARDWARE\\DESCRIPTIONHKEY_LOCAL_MACHINE\\HARDWARE\\DESCRIPTION\\SystemHKEY_LOCAL_MACHINE\\HARDWARE\\DESCRIPTION\\System\\FloatingPointProcessorHKEY_LOCAL_MACHINE\\HARDWARE\\DESCRIPTION\\System\\FloatingPointProcessor\\0 *SAM subkey: The system automatically protects it. *SECURITY subkey: Contains information about security settings, as well as protecting the system. *SOFTWARE subkey: Contains system software, currently installed application software, and user information. *SYSTEM subkey: This subkey stores the information used at startup and the information needed to repair the system, including description information and configuration information for each driver. There is only one CurrentControlSet subkey under the System subkey. The system saves the current driver control set information under this subkey. This introduces the Control and Services subkeys under the CurrentControlSet subkey. Control subkey This subkey holds information that is set by each icon program in the control panel. Since each icon program in the control panel may write information under different sub-keys, it is best for the user not to modify the information through the registry editor, otherwise the system may crash. (1) fontassoc subkey This subkey stores information about font settings (such as default fonts, alternate fonts, character sets, etc.). There are also two sub-keys Associated DefaultFonts, Associated CharSet under the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ fontassoc branch. The Associated DefaultFonts subkey has the following settings under the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\fontassoc\\Associated DefaultFonts branch: *AssocSystemFont=simsun.ttf: Defines the system font. Simsun.ttf is a TrueType Song font file. *FontPackage

DontCare=宋体: The following line sets the installed package font (FontPackage). In Win3.x, these settings are listed in the [FontPackages] section of the Wifeman.ini file. *FontPackageRoman=宋体*FontPackageSwiss=宋体*FontPackageModern=宋体*FontPackageScript=宋体*FontPackageDecorative=宋体 Associated CharSet Subkey Under the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ fontassoc\\Associated CharSet branch is some system font settings. (2) Nls subkey This subkey is located in the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ Nls branch. It is used to set the language features of Windows, such as code page, EUDC inner code range, language classification, and so on. (3) SessionManager subkey This subkey is used to manage the system's session. It consists of three primary keys and eight subkeys. KnownDLLs subkey This subkey contains 32-bit Dll files and identifiers in Windows. CheckBadApps subkey This subkey is used to check for problematic 16-bit applications that run into Windows with inexplicable problems and even crashes. There are many sub-keys of the application's executable under the subkey. For example, PPower.exe is MS DOS 6.x, a program for laptop power management. Its branch in the registry is HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\ Control\\SessionManager \\CheckBadApps\\POWER.EXE. Usually there are several subkeys under this branch! CheckBadApps400 subkey This subkey is used to check for problematic 32-bit applications. Its branch in the registry is HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ SessionManager\\CheckBadApps400. There are a number of subkeys for the application under the branch. These subkeys have the corresponding run settings for these applications. For example, UltraEdit32 is a 32-bit multi-function editor whose executable file is Ui32.exe, which is in the registry. The branch is HKEY_LOCAL_MACHINE\\System\\ CurrentControlSet\\control\\SessionManager\\CheckBadApps400\\ UE32.EXE. Below this branch is the Ui32.exe run settings (including the check mark of the executable Ui32.exe itself, the version check flag, its flag, etc.). AppPatches subkeys This subkey is used for application patches to make these applications work fine on Windows. In the Windows 3.x era, these patches were placed in the Win.ini file. This subkey is located on the HKEY_LOCAL_MACHINE\\System \\CurrentControlSet\\ control\\SessionManager\\AppPatches branch of the registry. There are many application subkeys and their settings below the branch. For example, there is a Setup application under this branch whose location is HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control \\SessionManager\\AppPatches\\SETUP. (4) MediaResources subkey This sub

key is used to set the multimedia resource, and its location is on the HKEY_LOCAL_MACHINE\\System\\ CurrentControlSet\\control\\MediaResources branch. The branch also includes DirectSound, Joystick, MIDINonGeneralMIDIDriverList subkeys and their settings. (5) MediaProperties subkey This subkey is located on the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ Media-Properties branch and is used to set the properties of the multimedia. (6) FileSystem subkey This subkey is located on the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ FileSystem branch, mainly for Windows NTFS and Win31, Win9.x file system settings. (7) Shutdown subkey This subkey is located on the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ Shutdown branch. It is used to set the Windows shutdown. Generally, there is a quick shutdown setting. (8) keyboard layouts subkey This subkey is located on the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ keyboard layouts branch, mainly for Windows keyboard layout (Keyboard Layouts) or keyboard language. The subkeys below include a number of subkeys for the keyboard language (also including the Chinese character input method), which are represented by numerical values. (9) Update subkey This subkey is located on the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ Update branch to determine whether the "Control Panel" window has been refreshed. The function of this subkey and the "View" in the "Control Panel" window. The "refresh" in the menu is the same. (10) TimeZoneInformation subkey This subkey is located on the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\TimeZoneInformation branch to set the time zone information. (11) Print subkey This subkey is located on the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ Print branch and is used to set up the printer. (12) IDConfigDB subkey This subkey is located on the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ IDConfigDB branch and is used to display other configuration information such as configuration data and configuration name of the hardware configuration file. (13) ComputerName subkey The subkey has the following hierarchy: HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ComputerName\\ActiveComputerNameHKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\ ComputerName\\ComputerName This hierarchy is used to set the computer name. (14) SecurityProviders subkey This subkey is located on the HKEY_LOCAL_MACHINE\\System\\CurrentControlSet\\control\\SecurityProviders branch and is used to set the security features of the network provider

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