Tài liệu Troubleshooting Aids phần 3 docx

Figure 13.14: In Windows XP and Windows Server 2003, the Uninstall button is disabled when you select TC/IP protocol in the Local Area Connection Properties window What if you want to reset the TCP/IP stack by returning it to its state when the operating system originally was installed? In Windows XP and Windows Server 2003, you can't remove and then reinstall it. However, there is a convenient way to work around this problem. To do so, you must use the netsh (NetShell) utility, which provides a command- line interface for configuring and monitoring Windows XP or Windows Server 2003 networking. In Windows XP, netsh utility provides a reset command, which rewrites registry keys related to TCP/IP. Consequently, you will get the same result as removing the TCP/IP stack and then reinstalling it. To reset TCP/IP settings in the registry, go to the command line (Start | Run, type cmd, and press <Enter> then issue the following command: netsh interface ip reset [log_file_name] Instead of log_file_name, use the name of the log file where the action will be recorded. If you don't specify the full path to the log file, it will be created in the current directory. The command will reset TCP/IP settings stored under the following registry keys: HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\ HKLM\SYSTEM\CurrentControlSet\Services\DHCP\Parameters\ Note If a log file already exists, the new log will be appended to the end of existing file. In addition, the contents of the log file depend on the system configuration. There may be times when no actions will be logged. This usually happens if the TCP/IP registry settings have not been changed since the original Windows XP or Windows Server 2003 installation. Troubleshooting Service Startup Problems Sometimes, you may encounter a service that can't start because of a logon failure. If this happens, the system might display error messages. Then, the next time you start the system, the following error messages may be in the system event log: Source: Service Control Manager Event ID: 7000 Description: The %service% service failed to start due to the following error: The service did not start due to a logon failure. No information in the Data field will be available. Source: Service Control Manager Event ID: 7013 Description: Logon attempt with current password failed with the following error: Logon failure: unknown user name or bad password. No information in the Data field will be available (Fig. 13.15 ). Figure 13.15: The Event Properties window displaying the error message on the service startup failure because of logon failure When you attempt to manually start the service, you will receive an error message informing you that the service could not start because of logon problems. This behavior can occur for any of the following reasons:  The account password the service uses to log on has been changed.  The password data in the registry has been damaged.  The right to log on as a service has been revoked for the specified user account. To resolve these issues, you can configure the service to use the built-in system account, change the password for the specified user account to match the current password for that user, or restore the user's right to log on as a service. If the right to log on as a service is revoked for the specified user account, you can restore this right. The procedure is somewhat different for domain controllers and member servers/client workstations. If the problem takes place at the controller of an Active Directory domain, proceed as follows: 1. Start the Active Director Users and Computers Microsoft Management Console (MMC) snap-in. 2. Right-click the organizational unit (OU) in which the user right to log on as a service was granted. By default, this is in the Domain Controllers OU. 3. Right-click the container, then click Properties. 4. On the Group Policy tab, click Default Domain Controllers Policy, then click Edit. This starts Group Policy Object Editor. 5. Expand the Computer Configuration object by clicking the plus sign (+) next to the policy object. Under the Computer Configuration object, expand Windows Settings, then expand Security Settings. 6. Expand Local Policies and click User Rights Assignment (Fig. 13.16 ). Figure 13.16: Restoring the right for the user account to log on as service 7. In the right pane, right-click Log on as a service (Fig. 13.17 ). Figure 13.17: The Log on as service Properties dialog 8. Add the user to the policy and click OK. 9. Quit Group Policy Object Editor, close Group Policy Properties, then close the Active Directory Users and Computers MMC snap-in. If the problem arises at the member server or a standalone computer, take the following steps: 1. Start the Local Security Settings MMC snap-in. 2. Expand Local Policies and click User Rights Assignment. 3. In the right pane, right-click Log on as a service, then click Properties. The Log on as service Properties window will open. 4. Add the user to the policy and click OK. Configuring Service Logon Information To configure the password for the specified user account to match the current password for that user: 1. Start the Administrative Tools applet in Control Panel, then double-click the Services icon. 2. Right-click the appropriate service, then click Properties. 3. The service properties window will open. Go to the Log On tab (Fig. 13.18 ), change the password, and click Apply. Figure 13.18: The Log On tab of the service properties window 4. Go to the General tab (Fig. 13.19 ), and click the Start button to restart the service. Figure 13.19: The General tab of the service properties window If the service starts, you have successfully eliminated the problem. In some situations, the service may not start with the specified user account. In such a case, you may reconfigure the service to start up with the built-in system account. Configuring the Service to Start Up with the Built-in System Account To configure the service to start up with the built-in system account: 1. Start the Administrative Tools applet in Control Panel, then double-click the Services icon. 2. Right-click the appropriate service, then select the Properties command from the right-click menu. 3. Go to the Log On tab (Fig. 13.20 ), set the Local System Account radio button, and click Apply. If the service needs to interact with the desktop, set the Allow service to interact with desktop checkbox. (Task Scheduler is an example of a built-in system service that requires interaction with the desktop.) Some third- party services, such as the F-Secure Authentication agent, also need to interact with the desktop. However, as most services don't need this feature, typically you may leave this checkbox unselected. Figure 13.20: Configuring the service to start up with the Local System account 4. Go to the General tab and click the Start button to restart the service. Using Registry Editor to Troubleshoot Service Startup Problems If you are able to start the Services tool, you can use the procedures described above to troubleshoot service startup problems. Sometimes, however, there may be situations when you are unable to use the Services administrative tool. For example, the computer may hang when you start this tool, and the following message may be displayed: The RPC Server is unavailable It is logical to suppose that the Services tool would not start because of a logon failure with the Remote Procedure Call (RPC) or a dependent service. Some services do not start until their dependent services have connected. For example, the Alerter service depends on the Workstation service (Fig. 13.21 ). To view the dependencies for a specific service, right-click the required service, select the Properties command from the context menu, and go to the Dependencies tab. As you can see, the dependencies list for the RPC service is quite long (Fig. 13.22 ). Figure 13.21: The Alerter service depends on the Workstation service Figure 13.22: The dependencies list for RPC service is quite long If a logon failure with the RPC service prevents you from starting the Services tool and using the safe method of configuring services, proceed as follows: 1. Start Registry Editor and locate the ObjectName value under the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ServiceName registry key. 2. Modify that value entry by setting its value to localsystem (Fig. 13.23 ), click OK, and quit Registry Editor. Figure 13.23: The ObjectName value under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ServiceName 3. Attempt to restart the service. You may need to restart the computer for some services to restart properly. If you cannot start Registry Editor, you can modify the service account information by performing a parallel installation of the operating system. Disabling a Service or Driver that Prevents Windows from Booting If you have managed to detect the service or device driver that prevents your system from booting, and if you have installed a parallel copy of the operating system that is bootable, you can try to eliminate the problem using the following procedures: 1. Boot into a parallel copy of the system and start Regedit.exe (Windows XP or Windows Server 2003) or Regedt32.exe (Windows NT or Windows 2000). 2. Go to the HKEY_LOCAL_MACHINE root key. 3. Use the Load Hive command to open the following registry file in the original Windows installation: %SystemRoot%\System32\Config\System [...]... valid startup options for device drivers include 0x0 (Boot), 0xl (System), 0x2 (Automatic), 0x3 (Manual), and 0x4 (Disabled) 7 After you have introduced all required modifications, unload the System 1 hive, quit Registry Editor, and try to reboot the original versions of Windows NT/2000/XP or Windows Server 20 03 ... suspected service>, where x is the value of Current: REG_DWORD o Change the value of start:REG_DWORD to 0x4 Note As outlined in Chapter 6, valid startup options for the service include 0x2 (Automatic), 0x3 (Manual), and 0x4 (Disabled) Thus, by setting the Start value to 0x4, you disable the service 6 To disable a device driver, proceed as follows: o Go to the HKEY_LOCAL_MACHINE\SYSTEM1\ControlSet00x\Services\ . 13. 23 ), click OK, and quit Registry Editor. Figure 13. 23: The ObjectName value under HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesServiceName 3. . Properties. 3. The service properties window will open. Go to the Log On tab (Fig. 13. 18 ), change the password, and click Apply. Figure 13. 18: The Log