Windows 98 is fully disclosed during system startup

Windows 98 is fully disclosed during system startup
Author: lava Source: Skynet responsibility Editor: wilderness

[Editor's note: A friend may be surprised to hear that Windows XP has come out. Why do I still write Windows 9x? I mainly consider two aspects: first, the technology is continuous, especially in the operating system. XP is developed on the basis of 9x, and its appearance does not mean that everything has never been pushed down, by understanding some technical knowledge of 9x, we can better understand the accessibility of version 2000 or XP. Second, many friends are still using version 9X, in terms of multi-system installation, optimization, game modification, system program development, and so on, Windows Startup knowledge is required. However, the information about Windows startup is messy and necessary to be retrieved from the source, let everyone systematically understand this knowledge. Based on this, the author has spent a lot of effort to collect this information .]

Directory

Windows 9x startup Overview
Boot Record
Io. sys
Msdos. sys
Command. com
Config. sys and autoexec. bat
Win. com
Gui startup
Summary of Windows 9x startup sequence
Conclusion

I. Windows 9x startup Overview

Since Windows 95 was released, Microsoft has insisted on keeping the kernel technology of Windows 9x confidential. It is always a black process for users to obtain the underlying technical information during Windows 9x startup. Understanding the starting process of the system is the key to fully controlling the system and optimizing the system. Now, based on public technical materials and practical experience, it is only from the application perspective, the startup processes of win 9x (including 95, 96 (95osr1), 97 (95 osr2.x), 98, and 98SE) are fully disclosed, and necessary technical details are described.

The Windows 9x family is mainly composed of four versions. Among them, Windows 95 is the first version, which creates a new era in the PC world and pushes Bill Gates to the throne of the richest man in the world. This version is not complete and has the most bugs. After more than a month of release, the revised software package will be provided.

Win 96 is the osr1 version of Win 95 (referred to as "96" because it was released in 96 years and 97 is the same). This version almost overwrites the kernel of Win 95, it corrected all kinds of problems in the practical application of Win 95. Since it was too close to Win 95, it was widely used.

Win 97 is the osr2.x of Win 95. This version has undergone a qualitative leap. The biggest change is that it provides the new disk format FAT 32 and integrates Internet Browser IE 3.0, this indicates that Microsoft's System Development Strategy has begun to shift to the Internet. Osr2.x has three versions: osr2.0, osr2.1, and osr2.5. osr2.1 supports USB and AGP graphics cards, and osr2.5 provides ie4.0. Because FAT 32 makes osr2.x incompatible with Win 95 and DOS, Microsoft only uses it as an OEM product and does not provide a retail version. Therefore, win 97 has become the most popular version after Win 95.

WIN 98 is the last glory of the Windows series based on DOS. It closely integrates Internet technologies with operating systems and provides ie4.0 and directx5.0, but does not provide anything more exciting, like the retail version of win 97.

Windows 98 SE is the second version of Windows 98. Compared with Windows 98, Windows 98 only provides ie5.0 and directx6.1a.

Windows 2000 is a network operating system based on Windows NT. It is already a completely different product from Win9x, and the new Windows ME is an alternative product of Windows 9X, however, in addition to the Windows 2000 interface, no updates have been found.

The evolution of Windows 9x is complex, but its core remains relatively stable without any fundamental changes. The startup process is almost identical, which is the basis of this article.

Ii. Guide records

Grass papaya Note: Unfortunately, I did not find this part on the Internet, but I have already explained it in detail in the "small discussion computer storage" series. See

Iii. Io. sys

1. Internal Startup menu of Io. sys

Io of win 9X. sys is composed of the original DOS system file IO. sys, msdos. combined with sys, the system provides standard hardware input/output interfaces and DOS interrupt calls. The function is fully enhanced. It basically controls all the startup processes of win 9X, is the core file of Windows dos real-mode. However, it must be set according to msdos. sys to enable the normal startup process.

Io. sys can be changed by the START function key. These function keys correspond to various options in the Start Menu:

Menu items corresponding to the function key
F4: Pre vious MS-DOS version
F5: Safe Mode
Shift + F5: Command Prompt only
F6: Safe mode with network support
F8: Bring up the Startup menu at startup
Shift + F8: Step-by-Step confirmation
When the system starts "Starting Windows 95...", press the function key.

Io. sys provides a menu for selecting the startup mode as needed:

(1) normal
Normal start mode (default start mode)
When bootwin is set to 0 in msdos. sys, selecting this system will start the old DOS version.

(2) Logged (bootlog. txt)
In normal startup mode, bootlog. txt is formed under the root directory.
Bootlog. txt records all the situations that occur during the startup process. It is the only comprehensive diagnosis record of the Windows 9x system startup process, which allows you to check problems during the startup process.

(3) Safe Mode
Security Mode gui. the four corners of the screen contain "security mode" and config is not loaded. sys, autoexec. bat does not load any programs in the startup program group, but only loads the most basic hardware configuration (standard VGA mode, no sound card, optical drive, etc.), that is, the simplest GUI startup, it is used to correct GUI startup problems caused by hardware configurations. When the system fails to start normally, the system enters the Startup Mode in most cases, but the problems solved in this mode are very limited, mostly used for display and other configuration system configurations are mainly adjusted on the control panel. To enter a normal GUI, you must restart

(4) step-by-step confirmation
Start Windows in one step
This method is used to determine the startup failure caused by system file damage. This method can only identify system problems during DOS Startup, and mainly fixes config. sys and autoexec. to identify problems in the GUI startup process, you can only use bootlog. TXT file

Using command prompt only
Only the complete real-mode DOS Startup Process is executed, and all DoS drivers that support Windows Startup are loaded in the pure DOS state, it is mainly used to run only applications in pure DOS mode or solve serious system problems. You can use the command win to start a normal GUI.

Using safe mode command prompt only the simplest DOS Startup only executes the most basic Io. sys, msdos. sys and command. the Default Driver (himem. sys, ifshlp. EXE and setver. EXE) and config. sys, autoexec. bat. The default values of other environments are the same as those of win 9x. This mode cannot start a normal or secure GUI, which is mainly used to handle the most serious system faults.

Explain previous MS-DOS version
Start the old DOS version and execute the dual-start command. The root directory should contain five original DOS system files saved with the. Dos extension. This option appears by msdos. note: When msdos is used. when bootwin = 0 in SYS, selecting this item will start the normal win 9x system secure safe mode with network support security mode with Real-mode network access this option appears by msdos. in sys, the parameter "network" control is used to eliminate PC faults of the network system. More system support can be obtained through the real-mode network system.

2. Default extended DoS configuration provided by Io. sys

Io. the biggest difference between sys and DOS at startup is that it provides the default config that can meet the requirements of most dos applications. sys configuration, which can automatically load necessary drivers to ensure that Windows 9x can be started properly. The details are as follows:

Himem. SYS: supports memory larger than 1 MB, and provides extended memory (XMS) management to ensure that files required for Windows Startup
Dblbuff. SYS: Dual cache driver, which is loaded only when needed. It is mostly used to support scsi
Ifshlp. EXE: An enhanced File Management driver that supports Win's vfat System
Ensure that files required for Windows Startup
Setver. EXE: Version Logon Service, which eliminates version restrictions and is only used in DOS
Dblspace. Bin: DOS 6.0 disk compression driver, which is loaded only when the hard disk is compressed
Drvspace. Bin: disk compression driver after DOS 6.22, same as above
DOS = high, umb: Move the dossystem into HMA to set aside more general memory, while umb does not have any effect on the system.
Files = 30: the maximum number of files that can be opened. It can be used only in DOS for most applications and is not required for win 9X.
Buffers = 30: set the maximum number of disk buffers to meet the requirements of most applications.
For DoS only, win 9x is not required
FCBs = 4: Number of file control blocks, which are rarely used now and only for DoS
Lastdrive = z: specifies the maximum drive letter. If the value is too small, the optical drive cannot be loaded.
Stacks = 9,256: set the number and size of stacks. This setting is not required for the old program to use win 9X.
Shell = command. com/P: Specify the win 9x command line handler.

Io. sys provides the following system environment settings:

Command query path: Path = C:/windows; C:/Windows/command
DOS prompt: prompt = $ p $ G
Temporary File directory: temp = TMP = C:/Windows/temp
Command Line Processing Program location: comsepc = C:/Windows/command. com

Io. sys provides complete system configurations, making it possible to cancel config. sys and autoexec. bat. For compatibility considerations, Io. sys does not load the emm386.exe driver, and does not provide extended memory EMS and upper memory umb. Emm386.exe may cause system crashes when the system searches for new hardware.

3. startup process under Io. sys Control

(1) when the system is started, Io. sys displays "Starting Windows 95...". At this time, you can select the start mode by the START function key.

(2) Io. sys determines the startup mode based on the menu selection and msdos. sys configuration.

(3) If the original DOS system is used, Io. sys automatically switches the system startup files of DOS and win 9x, and then controls the Startup Process of the original DOS system. (That is, the dual startup process of win 9x is ultimately controlled by Io. sys and has nothing to do with boot records)

(4) Io. sys starts with config. sys performs system hardware configuration. If config. sys does not load the required file for Windows 9x startup (such as himem. sys, ifshlp.. (If you want to load a driver that uses extended memory, such as emm386.exe, you must. add himem to the first line of SYS. SYS driver. Otherwise, emm386.exe and other programs cannot run because the system does not provide extended memory at this time)

After configuring the config. sys and other hardware, Io. sys calls autoexec. bat through command. com for software configuration.

Bootlog. txt in the root directory of the supervisor system is controlled by Io. SYS. Other log files are mostly created during system installation.

After the supervisor completes the DOS Startup Process, it automatically calls win. com to start the GUI.

Iv. msdos. sys

1. Functions of msdos. sys

In win 9x, msdos. sys is changed to a plain text system configuration file, which is used to control the start mode of win. Special Properties (read-only, hidden, and system) can be removed in DOS mode and configured as needed. Msdos. sys can be an empty file or even can be deleted. Of course, the system can only be started in pure DOS mode and cannot enter the GUI system.

Msdos is formed in different ways. the default sys content is different. There are four main types, among which msdos is formed by the first three methods. the sys file does not have any configuration commands. It is almost a blank file. Only one line of comments is retained to describe how the file is formed. Such files are mostly found in system floppy disks. Different msdos. sys contents are as follows:

1) System Disk created during Windows installation:; win95ebo
2) System Disk created by format/S:; format
3) sys A: pass to create a system disk:; sys
4) msdos. sys formed on the hard disk during system creation

Msdos in the system hard disk. sys is complete, including necessary startup configuration commands. The file length must be greater than 1024 bytes, that is, occupying more than two disk sectors. This requirement is described in this file to ensure compatibility, however, I have never discussed it further. In fact, the file smaller than 1024 bytes has no significant impact on the system. This requirement is estimated to ensure that the system and earlier versions of DOS and win 3. X compatibility, which is expected to be discussed by experts.

When sys is used to send the system to the hard disk to repair the Startup File, The Boot Record and IO will be overwritten. sys and command. com, msdos. the sys content remains unchanged, ensuring that the entire system can still be started properly after the system boot part is repaired. This approach is very clever.

2. msdos. sys configuration parameters

Msdos. sys consists of three small sections. The configuration parameters of msdos. sys have no order requirements. The content is as follows:
[Paths] specifies the Windows System File Path
WINDIR = Specify the directory of Windows 9x system files and Their subdirectories
This path must include the Registry File System. dat and win 9x to start required drivers, such as himem. sys.
Winbootdir = specifies the directory where the GUI Startup Program win. com of win 9x is located
Hostwinbootdrv = specifies the drive where win. com is located, without the need for a colon (:)
Uninstalldir = specifies the directory for saving the original system, so that the original system can be restored when the system is deleted.
This parameter appears in the upgraded version of win.
[Options] specifies the Windows startup mode. The value before/is the default value.
Logo = 1/0 allow/disable display of win 9x logo (logo) when starting)
Shielding this screen can sometimes resolve conflicts caused by third-party memory management programs. You can see the prompts during the system startup process, and enable the system to start faster.
Run the ESC key to clear the win 9x flag and view the instance startup information.
Bootkeys = 1/0 enable/disable the startup key to change the Startup Mode
When the value is 0, the default start mode is directly entered. The start hot key conversion cannot be used.
Bootgui = 1/0 enable GUI/only start dos 7.xto enter the DOS character Interface
When the value is 0, it is convenient for DOS 7.x to start multiple times and the graphic interface can be further started.
Bootwin = 1/0 start win 9x/start old dos, swap system files as required
When bootwin = 0, the old DOS version is started by default.
"Previous MS-DOS version" will start win 9x
Note: The bootwin level is higher than the bootgui level. If the two are in conflict, the previous level prevails.
Bootmulti = 0/1 disable/allow double start
Whether the "previous vertion of MS dos" item appears in the boot menu
This option is automatically displayed when Windows 9x is upgraded from the old DOS version and set to 1. But for Windows 97/98, if you do not modify the startup system, this option will cause the system to fail to start next time.

Bootmenu = 0/1 whether the Start menu is automatically displayed when the system starts
The value is 1. The start selection menu is displayed at startup.
Network = 0/1 whether the "Start in secure mode with network" item appears in the Start Menu
That is, "safe mode with network support"
Bootdelay = "Starting Windows 95... "Time, the default value is 2 seconds for you to use the startup key to change the startup mode. If this value is 0, no prompt is displayed to directly enter the default startup process, which can speed up the startup, however, you can still select the start mode as the start hotkey.

Bootmenudefault = the default option used by the Start Menu. The default value is 1.
Bootmenudelay = the default start delay period for the Start Menu. The default value is 30, and the Unit is seconds.
Bootsafe = 0/1 whether the system is started in safe mode. If the value is 1, the system is started directly in safe mode.
Bootwarn = 1/0 whether warning information is displayed at startup
When the system is shut down abnormally and restarted, does the system prompt "should enter safe mode"? In fact, the security mode has very limited problem solving capabilities. The real system problems cannot be solved in this mode.
Whether the single-step configuration mode can be used in bootconfig = 1/0 is unknown.
Disablelog = 0/1 whether to create bootlog. txt when "step-by-step config"
1: If you do not select your logged.txt, you do not need to query or create bootlog.txt.
0: Create a log file bootlog.txt.
Systemreg = 1/0 whether the Windows 9x registrar is running at system startup
1: "step-by-step config"
The Registrar is automatically run in other modes.
0: Do not run or ask if you want to run the Windows 9x Registrar
The register is run first before the entire system is started, but the running or not has no significant impact on the system. Its role is unknown.

Loadtop = 1/0 whether to load command. com, drvspace. bin, and dblspace. bin to high-end memory. If a memory address conflict occurs during startup, set this value to 0.
This type of conflict is mostly caused by the programs loaded by config. sys and autoexec. bat, which cause autoscan = 1/0.
Whether to automatically execute Scandisk during abnormal Shutdown (such as power failure) and restart
(Only valid in win 97/98)
Canceling the automatic detection of hard disks can eliminate some troubles, but it does bring potential risks to the system, but it is better not to close it.

Doublebuffers = 1/2/0 whether to load bdlbuff. sys, providing dual cache support
0: not provided; 1: provided as needed, such as scsi;
2: unconditional dual Cache
Dblspace = 1/0 allow automatic loading of the dblspace. Bin compression driver as needed (dos6.0, 6.2)
Drvspace = 1/0 allow automatic loading of the drvspace. Bin compression drive (dos6.22, win 9x)
Compressing hard disks reduces the overall system performance and increases the risk of data
Today, hard disk capacity is no longer a problem, so we still don't need to compress it.
Note that FAT32 does not support any disk compression software
Winver = indicates the official launch date of the Windows version.

The third part consists of any number of characters starting with a semicolon (;) in msdos. sys is a comment row and does not have any effect on the system. It is mainly used to ensure msdos. the sys file is more than 1024 bytes in length.

Most of the parameters provided by msdos. sys are used to adjust the system. For common users, common parameters include the parameters before network.
V. Command. com

Command. com is the DOS shell program (Shell) in Windows 9X. Compared with DOS 6.22, it only adds some internal commands and does not update anything.

Io. sys for command. the processing of COM has changed fundamentally. When win 9x is in config. command when the emm386.exe driver is loaded in sys to provide umb. the resident part of COM is mounted to HMA, and the temporary resident part is mounted to umb (in dos6.22, command. com can only load the resident part into HMA). This will provide a larger general memory for the DOS program, and does not need to recover the temporary part from the disk repeatedly, effectively improving the system performance. Of course, if emm386.exe is not loaded, the system does not provide umb. The temporary resident part of command. com can only be placed at the high end of conventional memory as dos6.22.

Vi. config. sys and autoexec. bat

Config. sys and autoexec. BAT in win 9x serve the same purpose as dos. They are used to assemble all DoS drivers and applications, or modify the default configuration of Io. sys. Among them, config. sys is mainly used for hardware configuration, and autoexec. bat is mainly used for software configuration. For how to use it during startup, see Io. sys.

After Windows 9x is started, the configuration of these two files is always kept at the bottom of the system as a global setting, which determines all the dos and win 16 application environments in Windows 9X. If there is no global DoS settings, the DOS application in the Windows window will use the default settings of win 9x, which can also be configured separately by the user. Note: environment settings such as path and set required by the DOS software can be set separately in the properties of their respective windows; Win 3 with 16 bits. environment settings such as path and set required by X software can only be set in autoexec. BAT.

Windows 9x has added many configuration commands to make the real-mode DOS environment easier to optimize. For more information about the configuration commands, see the system directory/config. txt description in windows. Win 9x uses VxD (Virtual Device Driver), DLL (Dynamic Link Library) and other protection mode drivers to manage and use system software and hardware resources in a unified manner, basically without the need for real-Mode Program support. The real-Mode Program is mainly reserved to support some old devices. The existence of the Real-mode program requires frequent conversion between the protection mode and the Real-mode of win 9x, which greatly reduces the system performance and damages the system stability, therefore, try to avoid loading the real-Mode Program at startup.

Windows 9x's default settings for the DOS environment can meet the needs of most DOS software. It is necessary to try to delete the content in these two files after Windows 9x is installed. Delete the real-Mode Program and try to implement the protection mode driver of win 9x, so that win 9x is in the optimized running state with high performance and high stability.

Dossystems without config. sys and autoexec. BAT have almost nothing to do, and their win 9x performance may be better. In win 9x, they are mainly reserved to support the original DOS software and old devices. At present, it is recommended that most newspapers Delete these two files completely. This is actually very problematic. For more information, see computer industry-computer experts, 'October.

7. Win. com

Win. com is a Windows GUI startup command. It can be seen from the file name that it is a pure DOS command, and it is also the only COM file in the GUI system. This command is an interface command for DOS and GUI. It is mainly used to load the protection mode Virtual Device Driver vmm32.vxd (this program is composed of multiple subprograms, enables the CPU to run in protected mode), and handles various problems during GUI startup. It controls the entire system calling process.

Various startup switches provided by win. com are mainly used to identify system faults and reduce system performance:

Win [/D: [f] [m] [s] [V] [x]

/D used to find the cause of failure when Windows cannot start normally

: F disables the 32-bit disk access mode for hard disks that do not support 32-bit access
It is equivalent to setting 32 bitdiskaccess = false in the [ENH] section of system. ini.

: Start in m safe mode, equivalent to start with function key F5

: N enable in Safe Mode Supported by the real-mode network. It is equivalent to using the function key F6 to start

: S disables Windows from using the ROM address space between f000: 0000 and 1 MB as a breakpoint.
It is equivalent to setting systemrombreakpoint = false in the [ENH] section of system. ini.

: V indicates that the hard disk controller is interrupted by the ROM routine during startup.
It is equivalent to setting virtualhdirq = false in the [ENH] section of system. ini.

: X disables Windows from using all high-end memory (from A000-FFFF) to solve memory conflicts
It is equivalent to setting emmexclude = A000-FFFF in the [effecenh] section of system. ini.

8. Gui startup

The GUI Startup Process of Windows 9x is very complicated, and is also the core secret of Microsoft, which is not known to outsiders. For common users, it is not necessary to fully master this complex and variable mechanism. Here, we will give a rough description of the overall GUI motivation.

1. Gui configuration file

Like all complex systems, win 9x is mainly used to call various programs based on the system configuration file to combine the systems to ensure the normal operation of the system. The GUI configuration file of win 9x takes the system registry as the core and the INI file in each system directory as the auxiliary configuration. Grasp the system configuration file to grasp the core of the system.

There are five core configuration files in the GUI system: win. ini, system. ini, system. dat, user. dat, and ES. dat.

Win. INI and system. INI is said to be win 3. X is retained by the win 16 Protection Mode Program. Win 3. X has been moved to the system registry in Windows 9X. In Windows 9x, the Windows 32 protection mode program is configured through the system registry without the support of these two files. This practice standardizes the development and use of applications, eliminates the confusion of setting INI files at will, facilitates win 9x unified management system, and increases system stability. However, if the two files are deleted, the Windows 9x system cannot be started and the system prompts "system. ini file cannot be found". This indicates that Windows 9x cannot be started without these two files.

Win. INI provides various information such as font settings and File Associations required by the win 16 program. It mainly completes the corresponding environment configuration in the GUI and has no significant impact on the win 9x application. If this file is not available, win 9x will automatically generate a simplest win with only a few lines of configuration commands. ini.

System. INI is different. It is the system hardware configuration file of win 16, and win 9x adds some new settings for it to ensure the coordination between win 16 and Win 32, so that win 16 can call the VxD driver, which is in win. the system debugging parameters provided by com are fully reflected. In addition, the GUI shell (Interface Program), mouse, display and other drivers must pass through the system. INI settings can be loaded and used, which determines the system. INI cannot be deleted. This fully proves that win 9x is a hybrid system of win 16 and Win 32, and reveals the root cause of the inherent weakness of win 9X.

System. dat and user. dat are the so-called system registry files, which are the core files of win 9X. Windows manages the entire system. System. dat stores hardware configuration and software installation information. User. dat stores information related to the user's personal settings. The former can only have one, while the latter can have multiple. These two files work together and contain all the information of the system. When the registry editing software (such as Regedit. EXE) is used, these two files are modified together and cannot be separated. Their damage will cause the system to be completely paralyzed and cannot be saved. Unfortunately, the system registry is very fragile and lacks self-organizing and maintenance mechanisms. After the system runs for a period of time, users can only embark on a painful road to rebuilding the system.

In Win 95/96/97, the Registry is backed up as system. da0 and user. da0, saved in/windows; in WIN 98, win. INI, system. INI, system. dat and user. the four DAT files are merged and backed up into a file rb00 ?. Cab, Which is saved in/Windows/sysbckup. By default, five are retained.

Each time the GUI is started, the system will automatically update the backup file. This kind of processing lacks a security management mechanism, which makes it difficult to ensure that the backup file is not disturbed by error information. In most cases, the backup file is virtually empty.

Unfortunately, win 9x does not provide a more effective registry maintenance tool except for manual registry software Regedit. EXE. At win 98th, I registered the Registration Table detection software scanreg.exeand scanregw.exe. This is an improvement. However, it can only handle physical faults in the Registry and cannot solve structural problems. What is its reliability?

The broad registry should be analyzed using a monograph. In trendy electronic essence 1, there is also a brief introduction, so I will not explain it further here.

Polices. dat is a Microsoft network registration support file, which is rarely used in China.

Although there is no direct information, there are good reasons to prove that during the start of win 9x, various INF files stored in the/Windows/INF directory are the most powerful supported files in Windows 9X. When starting the system, win 9x will call these files in time to load the corresponding driver. If these files are not available, Windows 9x cannot be started. In addition, win 9x's PNP technology is mainly installed by using the INF file.

2. Gui Startup Process

The GUI is started in three phases: wininit. EXE, 16-bit protection, and 32-bit protection.

(1) wininit. EXE stage win. after com starts running, first call wininit in/windows. EXE. This command looks for wininit in the same directory. INI. If yes, the system files are re-adjusted or upgraded according to the preparation of the file to ensure that the driver of the entire system is updated in a timely manner. This is the main way for Windows to support the PNP technology and upgrade the system driver. This process is naturally completed in the DOS state.

(2) Enable the 16-bit protection mode.

Win. after COM is started, call vmm32.vxd in/Windows/system, and vmm32.vxd puts the processor in protection mode. configure INI and registry to start the 16-bit protection mode of the GUI system. This ensures that the system supports Win16 software. More importantly, the pnp bios (plug-and-play BIOS) specification only provides 16-bit protection mode interfaces, win 9x, which uses PNP as the hardware technology core, must directly obtain the hardware device information provided by BIOS in 16-Bit mode to configure the system and improve the system startup performance, otherwise, the hardware configuration must start from the beginning in real mode.

To start the GUI, first load the Windows 9x system driver, and then obtain the hardware device information from the pnp bios, load the VxD driver of the PNP device and all the 16-bit virtual protection mode drivers required to support non-PNP hardware. Allocate system resources to avoid device conflicts, then Initialize all drivers (including system drivers and Device Drivers) to complete the system hardware configuration. Finally, load the 16-bit shell component user. EXE, Gui. EXE and krnl386.exe form Win16 APIs and start the 16-bit protection mode. At this time, each system component already exists, but the interface is unavailable.

(3) Enable the 32-bit protection mode.

After the 16-Bit mode is started, the system calls the 32-bit shell resource manager. When the 16-bit kernel sees this call, it automatically loads vwin32.386, it loads three 32-bit dll library files: user32.dll, gdi32.dll, and kernel32.dll to form a Win32 API (this is the core of win 9x). After vwin32.386 completes this task, return the control to the 16-bit kernel. Then, the 16-bit kernel gives the control to the 32-bit kernel and starts the 32-bit protection mode. In this case, the system loads and initializes all 32-bit drivers. The process is the same as that in the 16-Bit mode.

Finally, run the GUI shell program (the shell program is set by "shell =" in [boot] section of system. ini, which is the resource manager by default) to start the GUI.

3. troubleshooting during GUI startup

The GUI system is quite complex, but there are very few related technical materials, which makes it impossible for users to troubleshoot the fault according to the Startup Process in DOS.

Windows 9x provides no detailed description of the GUI startup process. Only a boot Log File bootlog. txt is provided in the root directory. This file records the loading of all program modules used during the startup process and is the only basis for solving system problems. Based on this record, you can fully understand the various problems that occur during GUI startup.

In the face of failures during the startup process, there are mainly two solutions: one is to overwrite the problematic program with a sound source program, but the difficulty lies in how to find the sound source program in various software packages, note: It is hard to imagine programs that directly debug and fix problems in Windows 9X. The first is from the startup configuration file (config. sys, autoexec. bat, win. INI, system. INI and registry. The latter is mainly used to solve the problem of a Software Uninstall failure.

There are many restrictions on solving system problems in the graphic mode GUI, while the pure DOS mode is not restricted by the system and is the final system door (for computer experts, DOS is still an eternal topic ).

The complexity of the Windows system determines the difficulty of troubleshooting those inexplicable faults. If the problem persists after several adjustments to the system, the safest and quickest way is to reinstall the system. Maybe this is Microsoft's only useful advice for users.

To reinstall the system in windows, make sure that the product serial number is consistent. Otherwise, the system may refuse to install the system.
　　
IX. Summary of Windows 9x startup sequence

This article discusses in detail the Startup Process of win 9x, the complex parameters and technical analysis blur its clear architecture, and now gives a brief summary of the entire startup process, this allows readers to judge the startup process relatively accurately based on the symptoms during the startup process to better handle problems during the system startup process.

(1) The system is powered on and started. The expansion card (including the video card) and the BIOS program of the motherboard are loaded in sequence (this is consistent with all operating systems (such as win 9x, Linux, UNIX, OS/2, etc) (independent) to complete the self-check process.

(2) read the Master Boot Record and Partition Boot Record of the hard disk and automatically load Io. sys

(3) Io. sys reads msdos. sys configuration, determines the startup mode, and configures hardware according to config. sys.

(4) Io. sys automatically loads necessary default drivers (himem. sys, setver. EXE, ifshlp. sys, etc.) According to Windows 9x startup requirements)

⑸ Io. sys calls command. com to explain how to execute autoexec. BAT for software configuration.

⑹ Io. sys to set the required default environment

Worker automatically runs win. com to enter the GUI startup stage.

Worker executes wininit. EXE to upgrade the system driver.

Worker loads drivers set in [boot], [ENH], and [devices] In system. ini.

Configure system combination and configuration based on system. ini, win. ini, and system registry. VxD files called during startup are mainly stored in vmm32 and iosubsys in C:/Windows/system.

Handler loads the shell program specified by "shell =" in system. ini

Scanregw.exe/Autorun of volume control and win 98.

When the user completes the identity logon, the system executes the applications contained in run and runonce in HKEY_CURRENT_USER → software → Microsoft → windows → CurrentVersion.

WORKER: run the load = run = loaded application in win. ini.

Applications in the [start] group in the worker execution Start Menu

Conclusion

The START process of win 9x is finally completed. Due to the limitations of my knowledge and vision, I have left many blank spaces to teach you how to master.

It is true that this process is a very old topic, but most of the introductions are limited to local skills, and there are many misunderstandings. It is rare to have a complete system, this has brought a lot of confusion to the majority of computer enthusiasts. Here, the ugly content is actually to correct some common misunderstandings, so that computer enthusiasts can have a relatively complete and clear grasp of the Windows 9x startup process.