Windows2000/XP startup process detailed

Windows2000/XP is an excellent operating system. It is powerful, secure and stable, and is favored by computer users. But in the process of use, we obviously feel that its startup time is much longer than Windows98, and it can test people's patience better than Windows98. Then, in this time of unbearable but unbearable time, what kind of work does the system do? Don't worry, let's take it slowly, and see why it is so fast.
On Intel-based computers, the Windows 2000/XP startup process can be roughly divided into five steps: pre-boot, boot, load the kernel, initialize the kernel, and log in to the user. The following is a separate introduction:
A. Pre-boot
First, the computer is powered on for self-test, and the BIOS (that is, the basic input and output system) completes the basic hardware configuration, and then reads the MBR (master boot record) of the hard disk to check the hard disk. The partition table is used to determine the boot partition and the operating system boot sector on the boot partition is called into memory for execution, where the NTLDR (Operating System Loader) file is executed.
* Windows 2000/XP supports multiple boot. It will first save the existing operating system boot sectors as BOOTSECT.DOS files (located under the active partition root directory) and modify the system boot sector so that the NTLDR file can be loaded at system startup to achieve multiple boot. the goal of. Windows98 does not have this feature, so if you install Windows2000/XP and then install Windows98, it will destroy the boot record of Windows2000/XP, and 2000/XP will not start.
II. Start
1. First, the initialization, NTLDR will convert the processor from real mode to 32-bit protection mode.
2. Read the BOOT.INI file. The file is located in the root directory of the active partition. Its role is to make the system select the menu during the startup process, and the user selects the operating system that you want to start. If you choose to start Windows2000/XP, NTLDR will continue to boot the following process; if you choose to non-Windows2000/XP system, NTLDR will read the system boot sector copy BOTSECT.DOS and boot into the corresponding system.
* Where [BOOT LOADER] is the operating system loader, which specifies the default waiting time for the system selection menu and the default boot operating system. It can be modified manually or modified in the control panel. For safety reasons, it is recommended to modify it in the control panel. You can change the settings by selecting Control Panel -> System -> Advanced -> Startup and Recovery. (There is another way to run msconfig (system configuration utility) in Windows XP.
[OPERATING SYSTEMS] section specifies the list of operating systems. The part enclosed by double quotes is the content displayed in the list. Modify to make it more personalized.
* A statement in the form of MULTI(0)DISK(0)RDISK(0)PARTITION(1) is called ARC path, and its format is: MULTI() - specify Disk controller (in the case of a SCSI controller, it should be replaced with SCSI()); DISK() - specifies the SCSI device number (the value is always 0 for MULTI); RDISK() - specifies the IDE device number (For SCSI, it is ignored here); PARTITION() - specifies the partition number. Except for the partition number starting from 1, the other numbers start from 0.
Parameter /FASTDETECT means that serial mouse detection is disabled, which is the system default. There are several common parameters: MAXMEM - specify the available memory capacity of Windows2000 /XP; BASEVIDEO - use the standard VGA display driver; NOGUIBOOT - does not display the graphical screen during startup; SOS - display when loading the device driver Its name.
* The Chinese font in the operating system selection menu is provided by the BOOTFONT.BIN file located in the root directory of the active partition.
3. The system loads the NTDETECT.COM file, which is used to detect machine hardware such as parallel ports, display adapters, etc. Etc., and return the collected hardware list to NTLDR for later registration and saving in the registry.
4. If Windows2000/XP has multiple hardware profiles, a selection menu will appear, waiting for the user to determine which one to use. Hardware configuration file, otherwise skip this step and enable the default configuration.
* Hardware configuration file refers to the system file that saves the specific hardware configuration of the computer. You can create multiple different hardware configuration files to meet the application of the computer in different occasions. You can change the control panel -> System -> Hardware -> Hardware Configuration File.
III. Load the kernel
The boot process starts loading the Windows2000/XP kernel NTOSKRNL.EXE. This file is located in Windows2000/XP installation. In the SYSTEM32 folder under the folder. Subsequently, the hardware abstraction layer (HAL) is booted by the process. , Completing this step
* hardware abstraction layer (HAL):. Hide platform specific details of the interface hardware, the operating system provides a virtual hardware platform, it has a hardware-independent, can be transplanted in a variety of platforms.
IV. Initialize the kernel
The kernel completes initialization, NTLDR transfers control to the Windows2000/XP kernel, which starts loading and initializing device drivers, and starts the WIN32 subsystem and the WINDOWS2000/XP service.
V. User login
Start the login process. Start WINLOGON.EXE by the WIN32 subsystem and start LOCAL SECURITY AUTHORITY (LSASS.EXE) to display the login dialog. After the user logs in, WINDOWS2000/XP will continue to configure the network device and user environment. Finally, with the voice of Microsoft and the personalized desktop we are familiar with, the long startup process of WINDOWS2000/XP is finally completed. Oh, is it asleep, wake up, the system starts successfully, what should you do now?