In this lesson, you learn about the tools and options Windows XP Professional provides to help you troubleshoot problems with starting your computer and recovering from disasters. These tools include safe mode, LastKnownGood configuration, the Recovery Console, and the Automated System Restore Wizard.
If your computer will not start, you might be able to start it by using the safe mode. Pressing F8 during the operating system selection phase displays a screen with advanced options for booting Windows XP Professional. If you select safe mode, Windows XP Professional starts with limited device drivers and system services. These basic device drivers and system services include the mouse, standard VGA monitor, keyboard, mass storage, default system services, and no network connections. Safe mode also ignores programs that automatically start up, user profiles, programs listed in the registry to automatically run, and all local group policies.
Safe mode provides access to Windows XP Professional configuration files, so you can make configuration changes. You can disable or delete a system service, a device driver, or an application that automatically starts that prevents the computer from starting normally.
If you choose to start your computer in safe mode, the background will be black and "Safe Mode" will appear in all four corners of the screen (see Figure 18.4). If your computer does not start using safe mode, you can try Windows XP Professional Automatic System Recovery.
There are a couple of variations of safe mode. You can select safe mode with networking, which is identical to safe mode except that it adds the drivers and services necessary to enable networking to function when you restart your computer. Safe mode with networking allows Group Policy to be implemented, including those implemented by the server during the logon process and those configured on the local computer.
A second variation of safe mode is safe mode with command prompt, which is similar to safe mode, but it loads the command interpreter as the user shell, so when the computer restarts it displays a command prompt.
Selecting the LastKnownGood configuration advanced boot option starts Windows XP Professional using the registry information that Windows XP Professional saved at the last shutdown.
If you change the Windows XP Professional configuration to load a driver and have problems rebooting, you can use the last known good process to recover your working configuration. The last known good process uses the LastKnownGood configuration, stored in the registry, to boot Windows XP Professional.
Windows XP Professional provides two configurations for starting a computer, Default and LastKnownGood. Figure 18.5 shows the events that occur when you make configuration changes to your system. Any configuration changes (for example, adding or removing drivers) are saved in the Current control set.
After you reboot the computer, the kernel copies the information in the Current control set to the Clone control set during the kernel initialization phase. When you successfully log on to Windows XP Professional, the information in the Clone control set is copied to the LastKnownGood control set, as shown in the lower part of Figure 18.5.
If you experience startup problems that you think might relate to Windows XP Professional configuration changes, shut down the computer without logging on, and then restart it. When you are prompted to select the operating system to start from a list of the operating systems specified in the BOOT.INI file, press F8 to open the Windows Advanced Options Menu screen. Then select the LastKnownGood Configuration option.
The next time you log on, the Current configuration is copied to the Default configuration. If your configuration changes work correctly, the next time you log on, the Current configuration is copied to the Default configuration. If your configuration changes do not work, you can restart and use the LastKnownGood Configuration option to log on.
Table 18.9 summarizes the purpose of the Default and LastKnownGood configurations.
Table 18.9??Default and LastKnownGood Configurations
Table 18.10 lists situations in which you can use the LastKnownGood configuration and the related solutions.
Table 18.10??Situations in Which to Use the LastKnownGood Configuration
After a new device driver is installed, Windows XP Professional restarts, but the system stops responding.
Use the LastKnownGoodConfiguration option to start Windows XP Professional because the LastKnownGood configuration doesn't contain any reference to the new, and possibly faulty, driver.
You accidentally disable a critical device driver (such as the Scsiport driver).
Some critical drivers are written to keep users from making the mistake of disabling them. With these drivers, the system automatically reverts to the LastKnownGood control set if a user disables the driver. If the driver does not automatically cause the system to revert to the LastKnownGood control set, you must manually select the LastKnownGood Configuration option.
Using the LastKnownGood configuration does not help in the following situations:
Pressing F8 during the operating system selection phase displays a screen with the Windows Advanced Options menu. This menu provides the following options:
Using an advanced boot option to boot the system sets the environment variable %SAFEBOOT_OPTION% to indicate the mode used to boot the system.
The Windows XP Professional Recovery Console is a text-mode command interpreter that you can use to access NTFS, FAT, and FAT32 volumes without starting Windows XP Professional. The Recovery Console allows you to perform a variety of troubleshooting and recovery tasks, including the following:
To install the Recovery Console, insert the Microsoft Windows XP Professional CD-ROM into your CD-ROM drive, and close the Microsoft Windows XP Professional CD dialog box, if it opens. Open a Run dialog box or a Command Prompt window in Windows XP Professional, change to the i386 folder on the Windows XP Professional CD, and then run the winnt32 command with the /cmdcoms switch. After you install the Recovery Console, you can use the Windows XP Professional CD-ROM to start your computer, and then to access the Recovery Console, select the Recovery Console option when you are prompted to choose repair options.
After you start the Recovery Console, you must specify which installation of Window XP Professional you want to log on to (if you have a dual-boot or multiple-boot configuration), and then you must log on as the Administrator.
You can also run the Recovery Console from the Windows XP Professional CD-ROM. The Recovery Console provides a limited set of administrative commands that you can use to repair your Windows XP Professional installation. You can use the following steps to start the Recovery Console from the Windows XP Professional CD-ROM:
Setup displays the Welcome To Setup screen. In addition to the initial installation of Windows XP Professional, you can use Windows Setup to repair or recover a damaged Windows XP Professional installation.
The Windows XP Recovery Console screen appears.
If you have more than one installation of Windows XP Professional on the computer, you are prompted to select which installation you want to repair.
You are prompted to enter the Administrator's password.
Setup displays a command prompt.
The computer will restart.
There are a number of commands available in the Recovery Console, some of which are described in Table 18.11.
Table 18.11??Recovery Console Commands
In this practice, you use the Windows XP Professional Recovery Console to troubleshoot a Windows XP Professional installation that will not boot. You also install and then start the Recovery Console, and you look at Help to determine what commands are available in the Recovery Console. You also use the Listsvc command to view the services and then use the Disable command to disable the Alerter service.
In this exercise, you troubleshoot a Windows XP Professional installation and repair it using the Recovery Console.
Windows XP Professional displays a Confirm File Rename dialog box asking if you are sure you want to rename the system file NTLDR to OLDNTLDR.
What error do you receive when attempting to restart the computer?
Setup displays the Welcome To Setup screen.
Setup starts the Recovery Console.
You are prompted to enter the Administrator's password.
Setup displays a C:\Windows command prompt.
Most of the files on the CD-ROM end with an _, for example, NTOSKRNL.EX_.
NTLDR is not compressed so you can copy it directly to your computer.
When the copy is complete, Setup displays a 1 file(s) copied message.
The computer reboots and should start normally.
In this exercise, you install the Recovery Console.
A Windows Setup message box appears, indicating that you can install the Windows Recovery Console as a startup option.
Windows Setup attempts to contact Microsoft and confirm that you have the latest version of Setup and then it installs the Windows XP Recovery Console on your hard disk.
Windows XP Professional displays a Microsoft Windows XP Professional Setup message box indicating that the Windows Recovery Console has been successfully installed.
In this exercise you use the Help command to view the available commands. You then use the available Listsvc and Disable commands.
The Microsoft Windows XP Recovery Console starts and prompts you to select which Windows installation you would like to log on to. If you had more than one Windows XP Professional installation on this computer, all of them would be listed here.
The Listsvc command allows you to view all the available services.
The Disable command allows you to disable a Windows system service or driver.
Recovery Console displays several lines of text describing how the registry entry for the Alerter service has been changed from Service_Demand_Start to Service_Disabled. The Alerter service is now disabled.
In this exercise you confirm that the Alerter service is disabled and then restart it.
The following questions will help you determine whether you have learned enough to move on to the next lesson. If you have difficulty answering these questions, review the material in this lesson before beginning the next chapter. The answers are in Appendix A, "Questions and Answers."