| The Device Manager enables you to check the status of computer hardware and update device drivers on the computer. It contains diagnostic features to resolve device conflicts and change resource settings. To access the Device Manager, you must open the System applet from the Control Panel. The Device Manager button is located on the Hardware tab, as shown in Figure 6.1. Figure 6.1. The Hardware tab of the System applet. 
 | Make sure you can install, update, and configure device drivers. |
Managing Drivers The Device Manager provides a graphical view of the hardware that is currently installed on the computer. The device drivers and resources associated with that hardware are listed in the properties of each device. Figure 6.2 demonstrates how the Device Manager provides a central point to change the way the hardware is configured. Figure 6.2. The Device Manager window. 
The Device Manager enables you to maintain, configure, and troubleshoot the devices physically connected to the computer system. The following items outline some of the available functionality: -
Determine whether the hardware is working properly on the computer. -
Change hardware configuration settings. -
Identify the device drivers loaded for each device and obtain information about each device driver. -
Change advanced settings and properties for devices. -
Install updated device drivers. -
Disable, enable, and uninstall devices. -
Reinstall the previous version of a driver with the Roll Back feature. -
Identify device conflicts and manually configure resource settings. -
Print a summary of the devices configured on your computer. Viewing Driver Properties When viewing Driver properties, you can determine the file version of the device driver. In the Device Manager window, an icon appears next to device drivers to indicate they are digitally signed by Microsoft. Windows device drivers and operating system files have been digitally signed by Microsoft to ensure their quality. A Microsoft digital signature is an assurance that a particular file is from that manufacturer and has been verified by Microsoft to function properly with Windows XP. Depending on how your computer is configured, Windows either ignores device drivers that are not digitally signed, displays a warning when it detects device drivers that are not digitally signed, or prevents you from installing device drivers without digital signatures. Figure 6.3 displays the Driver tab of the properties window of a network interface card. Figure 6.3. A Device Driver properties window. 
You can configure how the system responds to unsigned files by opening the System applet in the Control Panel and clicking the Hardware tab. In the Device Manager box on the Hardware tab, click the Driver Signing button to display the Driver Signing Options dialog box. There, you can set your system to the following options: -
Ignore ” This option allows files to be installed regardless of the digital signature. -
Warn ” This option displays a message before allowing the installation of an unsigned file. It is the default option. -
Block ” This option prevents the installation of unsigned files.  | When you are logged in using the Administrator account or are a member of the Administrator group , you can select Apply Setting as System Default to apply the driver signing configuration you set up to all users who log on to the computer. |
The File Signature Verification Utility enables you to monitor and troubleshoot digital signatures. You can access the utility from the Run command on the Start menu. Type sigverif.exe to open the utility window. After the utility opens, you can click the Advanced button to configure the verification options. Configuring Device Manager Views You can configure the Device Manager to display device information in various views. The following views are available: -
Devices by Type ” Displays devices by the type of device installed. The connection name is listed below the type. -
Devices by Connection ” Displays devices by how they are connected to your computer. Each device is listed under the hardware to which it is connected. -
Resources by Type ” Displays the status of all allocated resources by the type of device using these resources. The resources are direct memory access (DMA), channels, input/output ports (I/O ports), interrupt request (IRQ), and memory addresses. -
Resources by Connection ” Displays the status of all allocated resources by connection type. The resources are DMA channels, I/O ports, IRQ, and memory addresses. -
Show Hidden Devices ” Includes non “Plug-and-Play devices (devices with earlier Windows device drivers). | | Two types of devices are hidden by default in Device Manager. Non “Plug-and-Play devices, printers, and other classes of devices that are not typically useful in configuring or troubleshooting hardware issues are hidden. Also hidden are devices that were previously attached but are not connected to the computer at the present time, also known as nonpresent devices . Typically, you do not need to view hidden devices unless you need to configure or troubleshoot hardware. |
Updating or Changing a Device Driver You need to ensure that the latest device driver for each device is loaded in Windows XP. Manufacturers frequently update their drivers to fix problems and take advantage of operating system features. These drivers are usually available from the manufacturers' Web sites; Microsoft also maintains driver files for many devices on its Web sites. When downloading drivers, read the manufacturer's instructions before attempting to use the files to update the device. Downloaded driver files are typically compressed into a self-executing file that needs to be extracted to use the driver. In the Hardware Update Wizard, click to select the Have Disk option; then click the Browse button to locate the driver files. Because using the Device Manager is the most convenient method to update existing drivers, follow these steps to install updated drivers: -
From the Device Manager, expand the type of device you want to update or change.
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Right-click the specific device you want to update or change and select the Properties option.
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Select the Driver tab and click the Update Driver button to open the Hardware Update Wizard, as shown in Figure 6.4. Figure 6.4. The Hardware Update Wizard.  -
Accept the default option, Install the Software Automatically. Choose the Install from a List or Specific Location option if you have the updated driver so you can indicate the file location. Click Next.
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Windows searches for an updated driver and instructs you if an updated driver has been found. Install the updated driver and click Finish.
Rolling Back to a Previous Version of a Driver You use the Roll Back feature when you encounter problems after installing a driver. Such problems include error messages when you access the device, faulty device behavior, and even the inability to start Windows. To use the Roll Back feature with Windows XP, open the Device Manager and follow these steps: -
Right-click the device for which you want to reinstall the previous version of the driver and click Properties.
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Click the Drivers tab.
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Click the Roll Back Driver button.
| | The Roll Back feature certainly sounds like a blessing; however, for it feature to be effective, the original driver must still be stored on the system. If the driver has been removed or deleted, the Roll Back feature cannot install the previous driver. The Roll Back feature can also install the previous driver, but if it was not functioning properly, you simply install a nonfunctional driver. |
Troubleshooting Device Drivers Each device has its own device driver, but you can take some standard steps to troubleshoot driver problems. If a problem occurs with a device, a status box is displayed on the device in the device list. If the Device Status box displays a problem, click Troubleshoot to launch the Windows XP troubleshooter for this device type. The troubleshooter asks you to supply information and answer questions as prompted. If you cannot resolve the problem using the troubleshooter, visit the manufacturer's Web site. You are probably not the first person to encounter this problem, and the solution may be posted on the Web site. Table 6.1 summarizes the various symbols that may appear with a device that is not functioning properly. Table 6.1. Symbols Indicating Problems with Hardware Devices | Symbol | Explanation | | A black exclamation point (!) on a | The device is not functioning properly. yellow field | | A red X | The device as been disabled. | | A blue i on a white field | The device was manually configured. | | A green question mark (?) | A compatible driver is installed, but the device may not have all the functionality available. |
| | If a device's status is Disabled, that is usually the result of user action and does not necessarily mean the device has a problem. However, sometimes users disable a device because it was causing a problem, so you should try enabling it to see whether it affects another device negatively. If the device experiences a problem, the Device Status box displays the type of problem. You may see a problem code or number (or both) and a suggested solution. If you call a support line, this number can be useful for determining and diagnosing the problem. |
Handling Unknown Devices Listed in Device Manager When you view device information on your Windows XP computer using the Device Manager, you may see an unknown device listed next to a yellow question mark. Determining the cause of this unknown device can be difficult because there are few indications of what could be creating it. Some of the possible causes to this problem are -
The device does not have a driver. -
The driver is for an operating system predating Windows 2000. -
The hardware device is unrecognized. To solve these problems, you must install an updated Windows XP device driver for the hardware device. |
