Managing Computer Startups

Microsoft® Windows® 2000 Scripting Guide

Multiple operating systems can be installed on a single computer. Although servers are rarely configured in this way, workstations occasionally have multiple operating systems installed. For example, developers often do work on multi-boot computers for convenience in testing applications on different platforms. Workstations might need multiple operating systems if users need an application that runs only under a previous version of Windows. In addition, workstations are likely to have both the Windows operating system and the Windows Recovery Console installed.

As a system administrator, it is important to know:

  • Which operating systems have been installed on a computer.

  • Which operating system is loaded by default each time the computer is started.

  • Whether users are given enough time to load an alternate operating system during startup.

This information enables you to know what will happen to a computer anytime it is restarted.

The Windows Startup Process

When you start a Windows-based computer, it loads the operating system by using the following process:

  1. The computer runs a power-on self test (POST) that determines the amount of real memory installed on the computer and verifies the presence of required hardware components such as the keyboard.

  2. NTLDR, the bootstrap loader for the operating system, reads the file Boot.ini and displays the bootstrap loader screen, which is based on information found in Boot.ini.

    The screen display looks similar to the following:

    Please select the operating system to start:
    Windows 2000 Professional
    Windows 2000 Professional Recovery Console
    Use ® and  to move the highlight to your choice.
    Press ENTER to choose.
    Seconds until highlighted choice will be started automatically: 29
    For troubleshooting and advanced startup options for Windows 2000, press F8.
    
  3. NTLDR counts down the seconds. (By default, a user has 30 seconds in which to choose an operating system.)

  4. If the user does not select an entry before the counter reaches 0, NTLDR loads the default operating system specified in Boot.ini.