Kick-Start Startup with Boot.ini

After you install Windows 2000, a small, hidden, read-only text file—boot.ini—exists in the boot partition's root directory. This file is an important component in the machinery that controls the OS startup processes. The installation process creates the file's contents, so boot.ini is specific to the computer. Understanding boot.ini's format, its likely content, the conventions that its content follows, and your options for manipulating the file gives you two important elements of control over a system. First, you can change the file's contents to modify the startup process. Second, you can create a boot.ini file to repair a computer that won't boot.

You can edit boot.ini in any text editor. Before you do so, I suggest you copy the original file to a 3.5" disk in case your changes wreak havoc. Boot.ini is read-only, so you must change that attribute before you can save your edits. (Of course, don't forget to restore the read-only attribute when you've finished editing.)

Content: Boot.ini's Sections
All .ini files follow the same format rules. The contents are arranged in sections, and each section has a title enclosed in square brackets. As Figure 1, page 110, shows, boot.ini has two sections: [boot loader] and [operating systems].

The [boot loader] section contains a timeout specification and a pointer to the default OS's location. The timeout specification is the amount of time, in seconds, during which users can make a selection from the onscreen menu that appears when users have a choice of startup options. By default, the timeout duration is 30 seconds, and the default OS loads if users fail to make a choice within that time.

Typically, a choice of startup options occurs when more than one OS exists on the system (e.g., you updated a previous OS to Win2K and kept the previous OS, you installed two versions of Windows).

A choice also exists when you've installed the Recovery Console (RC), which automatically adds the Microsoft Windows 2000 Recovery Console option to the onscreen menu. (The RC is an advanced feature that you can use to repair a broken installation. For information about this feature, see Sean Daily, "Mastering the Recovery Console," July 2000.)

When users have no choices, no onscreen menu appears. The system ignores the timeout specification and immediately begins the OS startup.

Boot.ini's [operating systems] section contains the path or paths to the OS or OSs on the computer. As Figure 1 shows, text strings enclosed in quotation marks represent the text lines that the onscreen menu displays. You can edit the onscreen text to provide special instructions. For example, if you install a beta version of the next Windows version, you can edit the text to say Not for production.

Conventions: ARC Path Statements
The [boot loader] section's OS location information and the [operating systems] section's OS path information both follow the conventions in the Advanced RISC Computing (ARC) specifications. Win2K recognizes three ARC path structures: multi syntax, SCSI syntax, and signature syntax.

Multi syntax. Systems that utilize IDE hard disks commonly use the multi syntax in boot.ini. Using the multi syntax tells Win2K to depend on the computer BIOS to load the system files. The OS uses INT 13 BIOS calls to find the disk that holds ntoskrnl.exe and the other files the system needs to boot the OS. You can also use the multi syntax for SCSI drives if the SCSI device is configured to use INT 13 calls instead of the device's BIOS settings.