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WIN 9X mainly relies on system configuration files to call various programs to assemble the system and ensure its normal operation. The GUI system configuration in WIN 9X uses the system registry as the core, with the INI files in various system directories serving as auxiliary configuration.
The main core configuration files of the GUI system are: WIN.INI, SYSTEM.INI, SYSTEM.DAT, USER.DAT.
WIN.INI and SYSTEM.INI are said to have been kept for WIN 3.X WIN 16 protected-mode programs. Most of the settings from WIN 3.X in these two files had already been moved into the system registry in WIN 9X. Under WIN 9X, WIN 32 protected-mode programs mainly complete configuration through the system registry and do not need support from these two files. This practice standardized the development and use of applications, eliminated the confusion caused by arbitrarily setting INI files, made it easier for WIN 9X to manage the system in a unified way, and increased system stability. But if these two files are deleted, the WIN 9X system cannot start and will prompt “找不到SYSTEM.INI文件”, which shows that WIN 9X startup still cannot do without these two files.
WIN.INI provides the font settings, file associations, and various other information needed by WIN 16 programs, mainly completing the corresponding environment configuration under the GUI, and it does not have much effect on WIN 9X applications. If this file is missing, WIN 9X will automatically generate a very simple WIN.INI containing only a few configuration commands.
SYSTEM.INI is different. It is the system hardware configuration file for WIN 16, and WIN 9X also added some new settings to it to ensure coordination between WIN 16 and WIN 32, so that WIN 16 can call VXD drivers; this is already fully reflected in the system debugging parameters provided by WIN.COM. In addition, the GUI shell program (SHELL, that is, the interface program), mouse, display, and other drivers must be set through SYSTEM.INI before they can be loaded and used. These determine that SYSTEM.INI absolutely cannot be deleted. This fully proves that WIN 9X is a mixed WIN 16 and WIN 32 system, and also reveals the fundamental reason for the system’s innate fragility.
SYSTEM.DAT and USER.DAT are the so-called system registry files, the core files of WIN 9X, and WINDOWS uses them to manage the entire system. SYSTEM.DAT stores hardware configuration and software installation information, while USER.DAT stores information related to the user’s personal settings. These two files work together and contain all the system information. When using registry editing software (such as REGEDIT.EXE), these two files are modified together and cannot be separated. Damage to them will cause the system to collapse completely and be beyond recovery. Unfortunately, the system registry is very fragile and lacks self-organizing and maintenance mechanisms. After the system has been running for a period of time, the accumulation of various errors and BUGs produced during operation often leaves users with no choice but to rebuild the system.
In WIN 98, the four files WIN.INI, SYSTEM.INI, SYSTEM.DAT, and USER.DAT are merged and backed up into one file, RB00*.CAB, stored under \WINDOWS\SYSBCKUP, with 5 copies kept by default.
