The Windows NT Boot Process, The Windows NT Boot Sequence Process, Steps In The Intel-based CPU Boot Process

The Windows NT Boot Process

When a PC with Windows NT is first turned on, the boot load menu asks you to select an

operating system. You can control this menu from the System Properties box of the

Control Panel.

Click Start, Settings, Control Panel. The Control Panel allows you to configure

Windows NT, add hardware devices and software, and configure the environment for

applications.

Double-click on the System icon. The System Properties dialog box opens.

Click the Startup/Shutdown tab.

From the Startup drop-down list, select the operating system that you want to start

by default.

Select the number of seconds to wait before the system chooses the default option.

Also from this sheet, you can choose what you want the system to do when an

error occurs that prevents Windows NT from loading (called a fatal system

error). If you choose “Write an event to the system log,” you can view this

information under the event viewer. Microsoft support persons who diagnose

problems with booting can later use this information.

When you make changes and click OK, you are told that the system must reboot

before the changes take effect.

See also:

What Happens During The Windows NT Boot Sequence

Steps In The Intel-based CPU Boot Process

The Windows NT Boot Sequence Process

The following is a look behind the scenes of the boot process with a description of each step:

1. BIOS Executes POST. First, Startup BIOS performs POST, which happens just as it would regardless of the operating system present. After POST, BIOS turns to the hard drive to load an operating system.

2. BIOS Executes the MBR Program. The first thing in the partition information that BIOS needs is the MBR (Master Boot Record) containing the master boot program. The master boot program is the very first thing written in the first sector of a hard drive, followed by the partition table itself, and both are stored in the master boot sector. BIOS executes this master boot program, which examines the partition table, looking for the location of the active partition on the drive, and then turns to the first sector of the active partition to find and load the program in the boot sector of that active partition. So far in the boot process, nothing is different between Windows NT and other operating systems.

3. The MBR Program Executes the Operating System Boot Program. Remember that when DOS or Windows 9x boots the DOS boot sector contains the name of the initial operating system load program, IO.SYS. When Windows NT is installed, it edits this boot sector of the active partition, instructing it to load the Windows NT program Ntldr at startup, instead of IO.SYS.

Steps In The Intel-based CPU Boot Process

The following is an outline of the boot sequence for Intel-based computers:

Description Step

POST (power-on self test) is executed.

1. Performed by startup BIOS MBR (master boot record) is loaded, and the master boot program within the MBR is run.

2. Performed by startup BIOS Boot sector from active partition is loaded, and program in this boot sector is run.

3. Performed by MBR program Ntldr (NT Loader) file is loaded and run. (The Ntldr file is the initially executed Windows NT operating system file and is similar to IO.SYS in Windows 9x.)