Overview of the Boot.ini File

Overview of the Boot.ini File

The boot.ini file is a text file that contains the boot options for computers with x86 and x86-64 processors. It is located at the root of the system partition, typically c:/boot.ini.

The following sample shows the content of a typical boot.ini file.

[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)/WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)/WINDOWS="Microsoft Windows XP Professional" /fastdetect
C:/CMDCONS/BOOTSECT.DAT="Microsoft Windows Recovery Console" /cmdcons

The boot.ini file has two main sections:

• The [boot loader] section contains option settings that apply to all boot entries on the system. The options include timeout, the boot menu time-out value, and default, the location of the default operating system.

  The following sample shows the [boot loader] section of a boot.ini file.

  [boot loader]
  timeout=30
  default=multi(0)disk(0)rdisk(0)partition(1)/WINDOWS
  
  

• The [operating systems] section is comprised of one or more boot entries for each operating system or bootable program installed on the computer.

  A boot entry is a set of options that defines a load configuration for an operating system or bootable program. The boot entry specifies an operating system or bootable program and the location of its files. It can also include parameters that configure the operating system or program.

  The following sample shows the [operating systems] section of a boot.ini file on a computer with two operating systems, Microsoft Windows XP and Microsoft Windows 2000. It has two boot entries, one for each operating system.

  [operating systems]
  multi(0)disk(0)rdisk(0)partition(1)/WINDOWS="Microsoft Windows XP Professional" /fastdetect
  multi(0)disk(0)rdisk(0)partition(2)/WINNT="Microsoft Windows 2000 Professional" /fastdetect
  

   

 

Each boot entry includes the following elements:

• The location of the operating system. The boot.ini file uses the Advanced RISC Computing (ARC) naming convention to display the path to the disk partition and directory where the operating system resides. For example:

  multi(0)disk(0)rdisk(0)partition(1)/WINDOWS
  

• A friendly name for the boot entry. The friendly name represents the boot entry in the boot menu. The friendly name is surrounded by quotation marks and represents the boot entry in the boot menu. For example:

  "Microsoft Windows XP Professional"
  

• Boot entry parameters, also known as boot parameters or load options enable, disable, and configure operating system features. Boot parameters resemble command-line parameters, each beginning with a forward slash (/), such as /debug. You can have zero or more boot parameters on each boot entry.

  For a list of boot parameters relevant to driver testing and debugging, see Boot Parameter Reference.

 

You can have multiple boot entries for the same operating system, each with a different set of boot parameters. Windows creates a standard boot entry when you install the operating system, and you can create additional, customized entries for an operating system by editing the boot.ini file.

Comment

This document describes aspects of the boot.ini file that are of special interest to driver developers and testers. For a more general description of the boot.ini file on x86-based systems, including a list of commonly used boot.ini file parameters, see  Reviewing and Correcting Boot.ini Settings on x86-based Systems in the Microsoft Windows XP Professional Resource Kit Documentation.