Selecting the Operating System

NTLDR displays the bootstrap loader screen, where you can select an operating system to start. This screen is based upon the information in the Boot.ini file. The screen display is similar to the following:

Please select the operating system to start:

Windows 2000 Advanced Server

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.

If you do not select an entry before the counter reaches zero, NTLDR loads the operating system specified by the default parameter in the Boot.ini file. Windows 2000 Setup sets the default entry to the most recently installed copy of Microsoft® Windows NT® version 4.0 or earlier. You can edit the Boot.ini file if you want to change the default to either an earlier version of Windows 2000 or to another operating system.

Windows 2000 Setup places the Boot.ini file in the active partition. NTLDR uses information in the Boot.ini file to display the bootstrap loader screen from which you select the operating system.

The following is an example of a Boot.ini file:

[boot loader]

timeout=30

default=multi(0)disk(0)rdisk(0)partition(1)\WINNT

[operating systems]

multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows 2000 Server" /fastdetect

The Boot.ini file has two sections, [boot loader] and [operating systems]. You can use the parameters in the [boot loader] section to customize startup, as described in Table 15.2.

Table   15.2 Bootstrap Loader Parameters

Parameter

Description

Time-out

The time that the user has to select an operating system from the bootstrap loader screen before NTLDR loads the default operating system. If the time-out value is 0, NTLDR immediately starts the default operating system without displaying the bootstrap loader screen.
If you set this value to –1, NTLDR waits indefinitely for you to make a selection. You must edit the Boot.ini file directly because –1 is an illegal value for the System option in Control Panel .

Default

The ARC pathname to the default operating system.

Each entry in the [operating systems] section includes the ARC pathname to the boot partition for the operating system, the string to display on the bootstrap loader screen, and optional parameters. The bootstrap loader screen presented earlier in this chapter is an example of the use of this section of the Boot.ini file.

You can use the Boot.ini file to start multiple versions of the Windows 2000 operating system, as well as one other operating system, including Microsoft® MS-DOS®, Microsoft® Windows® 95, and Microsoft® Windows® 98.

Boot.ini Switches

The switches listed in Table 15.3, which can be added to the end of the [operating system] section of the Boot.ini file, are not case sensitive. For more information about the /MAXMEM and /SOS switches, see "Problem Occurs After the Bootstrap Loader Starts" later in this chapter. The switch you want to add must be placed on a separate line of the Boot.ini file.

Table 15.3 Boot.ini Switches

Switch

Description

/BASEVIDEO

The computer starts up using the standard VGA video driver. If you have installed a new video driver and it is not working correctly, you can select the Windows 2000 entry with this switch to start the computer and change to a different driver.

/BAUDRATE=nnnn

Specifies the baud rate to be used for debugging. The default baud rate is 9600 if a modem is attached, and 19200 for a null-modem cable. Including this switch in the Boot.ini file causes the /DEBUG switch to activate.

/CRASHDEBUG

The debugger is loaded when you start Windows 2000, but remains inactive unless a kernel error occurs. This switch is useful if you are experiencing random kernel errors.

/DEBUG

The debugger is loaded when you start Windows NT, and can be activated at any time by a host debugger connected to the computer. Use this switch when you are debugging problems that are regularly reproducible.

/DEBUGPORT= com x

Specifies the communications port to use for debugging, where x is the communications port that you want to use. Including this switch in the Boot.ini file causes the /DEBUG switch to activate.

/MAXMEM:n

Specifies the maximum amount of RAM that Windows 2000 can use. Use this switch if you suspect that a memory chip is bad.

/NODEBUG

No debugging information is being used.

NUMPROC=x

Allows you to force a multiprocessor computer to start up with < n processors.

/FASTDETECT =[COM x | COM x , y , z ...]

Turns off serial and bus mouse detection in NTDETECT. Use this switch if you have a component other than a mouse attached to a serial port during the startup process. If you use /FASTDETECT without specifying a communications port, serial mouse detection is disabled on all communications ports.

/SOS

Displays the device driver names as they are being loaded. Use this switch when startup fails (while loading drivers), to determine which driver is triggering the failure.

/PAE

Specify the /PAE switch with the corresponding entry in Boot.ini to allow a computer that supports physical address extension (PAE) mode to start normally. In safe mode, the computer starts using normal kernels even if the /PAE switch is specified.

Editing Boot.ini

When you install Windows 2000, the read-only, system, and hidden attributes of the Boot.ini file are set. Regardless of the value of these attributes, you can edit the timeout and default parameters in the Boot.ini file using the System option in Control Panel.

To edit the Boot.ini file with a text editor, you need to make the file visible and turn off the read-only attribute. You can change file attributes using My Computer or at the command prompt.

To change file attributes using My Computer

  1. On the Tools menu, click Folder Options .

  2. On the View tab, double-click Hidden files and folders .

  3. Select either Do not show hidden files and folders or Show hidden files and folders .

  4. Click OK .

important-icon

Important

If you change the path to the Windows 2000 boot partition, make sure to edit both the default path and operating system path entries. If you change one but not the other, a new choice is designated as the default selection and added to the bootstrap loader screen.