Registry and its backup and recovery

Replacing DOS with Windows9x has become an option for the operating system. With the rich functions, the management details of Windows 9x far exceed DOS. You cannot modify the configurations and status of Windows only by modifying AUTOEXEC or CONFIG. They need to be stored, classified, and edited in a new way. As a result, the Registry, which allows countless users to "change" their minds, came into being. You can use it to gain a deeper understanding of Windows 9X. Because the registry is used in Windows 9x, You can flexibly configure the hardware and software of the computer system as required.

I. Windows Registry

1. What is the registry?

The Registry is an internal database of Windows and a huge tree-layered database. It contains all configuration information for applications and computer systems, initialization information for systems and applications, associations between applications and document files, descriptions, statuses, and properties of hardware devices, and various status information and data. The registry stores various parameters and directly controls Windows Startup, hardware driver loading, and running of some Windows applications, thus playing a core role in the entire Windows system. It includes the following content:

(1) software and hardware configuration and status information. The registry stores the initial conditions, preferences, and uninstallation data of the application and resource manager shell.
(2) settings of the entire system of the networked computer and the associations between various licenses, file extensions and applications, and descriptions, statuses, and properties of hardware components.
(3) performance records, other underlying system status information, and other data.
If the registry is damaged, Windows may encounter an exception during startup. Otherwise, the entire system may be completely paralyzed. Therefore, it is very important for Windows users to correctly understand and use it, especially to back up data in time and restore the Registry when problems occur.

2. Registry File:. DAT

Windows 98 stores all registry files in two files: System. dat and User. dat. They are binary files and cannot be viewed in a text editor. They are stored in the Windows directory and have implicit, system, and read-only attributes. System. dat contains computer-specific configuration data, such as information about installed hardware and device drivers. User. dat contains User-specific data, such as desktop settings, wallpaper and window color settings. User. the dat file is located in the C \ Windows \ profiles \ USERNAME directory when you log on with a user name, the system also keeps a default User in the C \ Windows directory. dat file for new users.

Note: The files System. da0 and User. da0 belong to Windows95 and are backup files of the Registry. They are created after the System starts successfully each time. In Windows 98, the Registry checker makes the backup file a CAB file.

Ii. Registry Editor-Registry Editor

1. Open Registry Editor

The open method of the Registry is very simple. Click the start button of Windows, find run, and left click. In the displayed dialog box, enter regedit and click OK.

We can see that in the registry, all the data is organized in a tree structure using keys and subkeys, which is very similar to the directory structure. Each key contains a specific set of information. The key name of each key is related to the information contained in it.

2. Basic operations of Registry Editor

The Registry Editor provides some basic operation commands. Here, we use the current Desktop as an example to describe the basic operations of the Registry Editor.
(1) Open HKEY_CURRENT_USER \ Control Panel \ desktop \ WindowMetrics. Some names and data are displayed in the window on the right.
(2) Right-click the right pane of the editor and a shortcut menu will pop up. You can select it to create a primary key, a string, a binary value, or a DWORD Value.
(3) Right-click the desktop keyword in the left pane of the editor and a shortcut menu will pop up. Here, you can create a new primary key, string value, binary value, or DWORD Value, you can also perform search, delete, and rename operations.
(4) double-click the keyword name in the right pane of the editor. an edit window is displayed, where you can adjust the constant value, delete the constant, and rename the constant, for example, double-click the string "ScreenSaveActive" to bring up the 2 dialog box.

Iii. Registry backup and recovery

When installing new applications or adding new hardware, the registry of the system may be messy, causing unexpected events. Therefore, users should be backed up regularly. dat and system. dat file (Editor: we strongly recommend that you back up the registry before modifying the registry to prevent system crash due to misoperation during modification ).
In the Windows directory of Windows 98, the System. dat and User. dat files are still used to store the System registry information. Next I will talk about several common methods to back up and restore the Registry in Windows 98 based on my own experience.

1. Direct backup and recovery

This is a very primitive method, that is, directly apply the required System. dat and User. the dat files are copied to a specified directory on the hard disk or directly copied to a floppy disk as a backup. After the backup is restored, replace the backup with the original one, of course, you must modify the read-only and hidden attributes of these two files during backup and recovery to display the hidden files.

Note: If the system is paralyzed due to a registry problem and cannot enter the Windows system after startup, you can use an emergency boot disk to enter the built-in DOS interface of Windows 98, use conventional DOS operations to overwrite the backup in a hard disk or floppy disk to restore the backup registry data.

2. Export and import the Registry Editor

Run regedit.exe to open the windows 98 registry, and use the "Export" and "import" functions of "Registry" to back up or restore registry information. For details, click the "Registry" drop-down menu in the upper left corner of the "Registry Editor" window and click "Export registry file ......" In the displayed "Export note table file" dialog box, type the file name and storage location of the Registry to be backed up, and then press the "save" button. To restore the registry, open the Registry Editor in the same way, open the "Registry" drop-down menu, and click "Import registry file ......" Item, select the backup file to be restored in the displayed dialog box, and then press the "open" button to restore the note table back to Windows.
Note: This method is applicable to restoring the Registry when Windows is not paralyzed or when Windows 98 is started in safe mode. If a Windows system cannot be accessed due to a registry problem, this method is powerless.

3. Automatic registry backup

In Windows 98, the System is automatically used every time Windows 95 is started. da0 and User. the da0 file is used to back up the registry data. cab (Cabinet) uses a compressed file with a suffix as the registry backup function, as follows:

The backup process is automatically completed by Windows 98. When you start the System for the first time on the same day, Windows98 will automatically record the original table information, including System. dat, User. dat, System. ini and Win. ini files are compressed into files in the form of a Cab. files such as rb000.cab and rb001.cab are compressed in the Windows \ Sysbacup directory, these are the five most recent system backups (Windows \ Sysbckup is a hidden directory, and the hidden files and directories must be displayed for viewing ). The system automatically saves the registry data for the last five boot times.

In general, after Windows 98is installed, scanregw.exe/autorun will be automatically run at startup to back up the registry once a day. You can choose to run "Msconfig" on the "Start" menu, run Microsoft's System Configuration program, and click "start" to check whether the command is run. If the command is not run, run the Registry Editor "Regedit ", create a new string value under the primary key "HKEY_LOCAL_MACHINE \ Soft ware \ Microsoft \ Windows \ CurrentVersion \ Run, the key value is "C \ Windows \ scanregw.exe/autorun" (here, the installation directory of Windows 98 is C \ Windows ). In this way, Windows 98 automatically backs up the last five registries and stores them in the C \ Windows \ Sysbckup \ path as rb00.cab.