Boot Options

Windows XP offers several alternate boot methods which can be used to bypass a problem or boot into a reduced environment so you can solve the problem. If you can't boot the system, this is the time to start considering the boot options. For example, if you've recently installed a new device driver that caused a serious system failure (you can't boot), you can use a boot option to boot without that driver (this is called the "Last Known Good Configuration," to be exact).

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If you can boot, but you're being plagued by other strange system anomalies, read the "System Restore" section later in this chapter. It might be a better choice for a simple repair. If you can boot, but a device isn't working after having just installed a new driver, check the section on "Driver Rollback," in Chapter 30.

The boot options of Windows XP are accessed during the early stages of system startup. If you have more than one OS on your system, the boot menu will be displayed. You'll have until the counter reaches zero to press F8. If you have only Windows XP Pro on your computer, you'll see a message about pressing F8 after the computer's own Power-On Self Test and the display of the graphical booting screen. You'll have only a few seconds, so keep your finger over the F8 button and press it when the message appears. Pressing F8 at the correct moment reveals the Advanced Options Menu which contains several boot options. These options are listed in Table 33.1.

Table 33.1. Safe Mode Startup Options

Option	Description
Safe Mode	Starts Windows XP using only basic files and drivers (mouse, except serial mouse devices; monitor; keyboard; mass storage; basic video; default system services; and no network connections).
Safe Mode with Networking	Starts Windows XP using only basic files and drivers, plus network connections.
Safe Mode with Command Prompt	Starts Windows XP using only basic files and drivers. After you log on, the command prompt is displayed instead of the Windows desktop.
Enable Boot Logging	Starts Windows XP while logging all the drivers and services that were loaded (or not loaded) by the system to a file. This file, called ntbtlog.txt, is located in the %windir% directory. Safe Mode, Safe Mode with Networking, and Safe Mode with Command Prompt add to the boot log a list of all the drivers and services that are loaded. The boot log is useful in determining the exact cause of system startup problems.
Enable VGA Mode	Starts Windows XP using the basic VGA driver. This mode is useful when you have installed a new driver for your video card that is causing Windows XP to hang or start and lock up half-way into the initialization process. The basic video driver is always used when you start Windows XP in Safe mode (Safe Mode, Safe Mode with Networking, or Safe Mode with Command Prompt).
Last Known Good Configuration	Starts Windows XP using the Registry information that Windows saved at the last shutdown. Use this option only in cases in which you strongly suspect a program has written incorrect or damaging information to the Registry. The last known good configuration does not solve problems caused by corrupted or missing drivers or files. Also, any changes made since the last successful startup are lost.
Directory Services Restore Mode	This option is valid only for domain controllers.
Debugging Mode	Starts Windows XP while sending debug information through a serial cable to another computer.
Start Windows Normally	This option boots the system without altering the normal boot operation. Use this selection to return to normal booting after you've made any other selection from the advanced menu. Selecting this option causes the normal boot to occur immediately; you will not be returned to the boot menu.
Reboot	This command reboots the system immediately, without first booting into Windows XP or even returning to the boot menu.
Return to OS Choices Menu	This command returns to the boot menu without making an alternate boot selection.

After you've made a selection from the Advanced Options Menu, you are returned to the boot menu (Unless Reboot or Start Normally is chosen, of course). Notice your selected option is listed in blue at the bottom of the screen. From this point, you can select an OS from the list and continue with booting based on your selections.

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If a symptom does not reappear when you start in Safe mode, you can eliminate the default settings and minimum device drivers as possible causes.

Using Safe mode, you can start your system with a minimal set of device drivers and services. For example, if newly installed device drivers or software is preventing your computer from starting, you might be able to start your computer in Safe mode and then remove the software or device drivers from your system. Safe mode does not work in all circumstances, especially if your system files are corrupted or missing, or your hard disk is damaged or has failed.

In general, if you've just performed some operation that caused a system failure, the best first reboot action is to use the Last Known Good Configuration. If that fails to resolve the issue, use Safe Mode. If the problem is specific to the video drivers (or suspect that it is), you might want to use Enable VGA Mode instead of Safe Mode. If you've just recently changed video drivers or the video card itself, you may want to use the Enable VGA mode if things don't act normally during the reboot.

When you are able to access the system through Safe Mode, you need to resolve the issue causing the boot problem. In most cases, this will require you to reverse your last system alteration, application install, driver update, and so on. If your system stops booting properly and you did not make any changes, then you should probably call Microsoft tech support. They may be able to help track down the culprit and get things back on track.

If none of these boot options results in a repaired system or offers you the ability to boot the system, you'll need to move on to the Recovery Console.