Composition and Analysis of Windows operating system registries (1)

Composition and Analysis of Windows NT Registry

Like Windows 9x, Windows NT also has a registry. The Registry is an important database for saving system configurations. However, compared with Windows 9x, it only contains five parts:
(1) HKEY-LOCAL-MACHINE: used to save the information of the local system, including hardware and operating system data, such as driver, system configuration information;
(2) HKEY-CLASS-ROOT: used to save associated information;
(3) HKEY-CURRENT-CONFIG: save data related to the current hardware configuration file;
(4) HKEY-CURRENT-USER: save the environment settings data related to the current login user, including desktop settings, network connections, etc;
(5) HKEY-USERS: stores all user profile data that must be loaded when a user logs on, including the default profile and the publisher's Environment profile.
In addition, to start the Registry Editor in WINNT, run the "Start/Run" command, enter REGEDIT32.EXE (instead of rededit.exe of Windows 9x) in the "run" dialog box, and click OK.
Composition and Analysis of Windows Me Registry
Unlike Windows 98, the WinMe registry is named "Classes" under the Windows directory. dat, User. dat (user configuration information) and System. dat (system configuration information) is composed of three binary files. The "item value" is the same as Win 98 with the string value REG_SZ), the binary value REG_BINARY), and the dual-byte value REG_DWORD) three types.
Similar to Win 98, WinMe also has a Registry Editor Windows \ Regedit.exe, as shown in figure 1), which is used to search for or modify the registry.

In the left window of WinMe Registry Editor, the top layer is "My Computer". There are six branches: HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_USERS, HKEY_CURRENT_CONFIG, and HKEY_DYN_DATA, A brief description of the functions of each branch is shown in table 1.

Branch name	Merit
Hkey_classes_root	All users must use this branch to store the types, extensions, and associations with applications of open files.
Hkey_current_user	Save the system settings, control panel options, and mapped network drive of the current Login User?
Hkey_local_machine	Saves all hardware information on the machine and application software information installed on the machine.
Hkey_users	Stores information about all users, such as installed applications and custom desktops.
Hkey_current_config	Computer-connected hardware, such as monitors and printers) configuration data
Hkey_dyn_data	Saves dynamic information about system performance and plug-and-play status

Brief description of features of six WinMe registries

Compared with Win 98's Regedit, WinMe's Registry Editor function has been increased, as shown in:
1. With the memory function, the tree primary key branch in the left window is automatically expanded each time it is opened, and the focus is located at the last modified position;
2. the IE-like favorites menu is added in the menu bar, which provides the favorites function to add and delete favorites), allowing you to quickly locate the primary key location to be modified.
If you need to check which programs are automatically transferred during system startup, you can open HKEY_LOCAL_MACHINE \ Software \ Microsoft \ Windows \ CurrentVersion \ Run and HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Run, find the two items in the Registry Editor of Win 98. You need to double-click the branch multiple times to open the level-1 and level-1 registry items. In WinMe, this operation is much easier, you only need to add the preceding two items to the favorites folder of the Registry Editor, and open the favorites item as if you were using IE. To add a registry to favorites, click "add to Favorites" in the menu. In the displayed dialog box, name the favorites item and press "OK ".
Windows2000 Registry
Windows 2000 stores its configuration information in a database named registry, which contains the configuration files for each computer user and information about system hardware, installed programs, and attribute settings, windows 2000 always references this information during running. The Registry is stored in binary format on the hard disk. incorrectly editing the registry may seriously damage the system. Therefore, we strongly recommend that you back up the registry information before changing the registry. To prevent fatal errors when modifying the registry, it is necessary to understand the backup and recovery methods of the Registry file. To study the Registry structure, you can save a primary key or subkey in the registry as a text file or print it out, to do this, you also need to know how to import and export registry files.
1. Comparison between Windows 2000 and Windows 98 registries
You may be familiar with the Windows 98 registry, but windows is different from Windows 98 after all. This article will take Windows 2000 Professional version as an example to introduce the Winsows2000 registry.
First, run the Registry Editor. You can select "Start/Run" in the menu, enter "regedit" in the pop-up dialog box, and then click "OK" to start the Registry Editor (1) similar to Windows 9X ). As you can see, the HKEY_DYN_DATA Root Key is removed from the content of Win98. There are only five root keys: KEY_LOCAL_MACHINE, HKEY_CLASSES_ROOT, HKEY_CURRENT_CONFIG, HKEY_USERS, and HKEY_CURRENT_USER. It provides many functions than the Registry Editor in Windows 9X. First, the type column is added to the detailed list of key values in the right window, so that we can intuitively understand the type of the key value, for example, REG_SZ is a string value, REG_DWORD is a DWORD value, and REG_BINARY is a binary value. Secondly, a menu similar to IE is added to the menu bar, which provides the favorites function, it allows you to quickly locate the primary key location that needs to be modified frequently. Third, it also provides the memory function, that is, each time you open it, the tree-like primary key branches in the left-side window will be automatically expanded to focus on the position you have recently modified.
In addition to the Registry Editor similar to Windows 9X, Windows 2000 also provides a new version of Registry Editor. Note: The registry modifications we will introduce are all performed here.) The location is in D: \ WINNT \ system32 \ regedt32.exe suppose D is the installation drive letter of Windows 2000), run it, as shown in main interface 2.

In addition to all functions of the original Windows 9X Registry Editor, this new Registry Editor adds the "Security" menu, that is, the administrator can assign "Permissions" to registry keys ", this feature has long been used in NT, but it is provided for the first time in a single-host operating system. This greatly improves the security of the Registry. The following example describes how to assign "Permissions" by allowing users to access the "control panel" registry key without saving any modifications to it ". Click the "Control Panel" primary key in the [HKEY_CURRENT_USER] window, select "permission" in the "Security" menu, and select a user in the "Control Panel Permissions" dialog box, select the "allow" check box on the right of "read" and click "OK.

The Registry Editor has multiple subwindows (4). Each subwindow represents a predefined item on the local computer, that is, five root keys ). This registry editor not only displays and edits the registry key of the local computer, but also accesses the registry of the remote computer. when accessing the registry of the remote computer, you can only use two predefined meanings: [HKEY_USERS] and [HKEY_LOCAL_MACHINE].