Windows XP Professional supports both Plug and Play and non-Plug and Play hardware. This lesson introduces you to the automatic hardware installation features of Windows XP Professional. Occasionally, Windows XP Professional fails to automatically detect a hardware device. When this occurs, you must install the hardware device manually. You might also have to do this if the device requires a specific hardware resource to ensure that it is installed properly.
Windows XP Professional supports Plug and Play hardware. For most devices that are Plug and Play-compliant, as long as the appropriate driver is available and the basic input/output system (BIOS) on the computer is a Plug and Play BIOS or an Advanced Configuration and Power Interface (ACPI) BIOS, Windows XP Professional automatically detects, installs, and configures the device. When there is a new piece of hardware detected that cannot be installed automatically, Windows XP Professional displays the Found New Hardware Wizard (see Figure 11.1).
Figure 11.1 The Found New Hardware Wizard
However, you might occasionally need to initiate automatic installation for some Plug and Play hardware. You do this with the Add Hardware Wizard. For non-Plug and Play hardware, Windows XP Professional often identifies the hardware and automatically installs and configures it. For non-Plug and Play hardware that Windows XP Professional does not identify, install, and configure, you initiate the automatic installation of the hardware with the Add Hardware Wizard.
To automatically install hardware, complete the following steps:
Windows XP Professional queries the hardware about the hardware resources that it requires and the settings for those resources. A hardware resource allows a hardware device to communicate directly with the operating system. Windows XP Professional can resolve conflicts between Plug and Play hardware for hardware resources.
After Windows XP Professional finishes the installation, you should verify correct installation and configure the hardware.
You can also use the Add Hardware Wizard to initiate automatic hardware installation for undetected hardware devices, both Plug and Play and non-Plug and Play, and to troubleshoot devices.
To start the Add Hardware Wizard, do the following:
Windows XP Professional starts the Add Hardware Wizard, which is used to install software to support the hardware you add to your computer and to troubleshoot problems that you might be having with your hardware.
You can also click System in the Performance And Maintenance window accessed from Control Panel and start the Add Hardware Wizard from the Hardware tab of the System Properties dialog box.
Windows XP Professional searches for new devices and one of the following three events occurs:
Figure 11.2 Adding hardware or troubleshooting with the Add Hardware Wizard
To use the Add Hardware Wizard to troubleshoot a hardware device, click the device in the list of installed hardware devices and click Next. The Completing The Add Hardware Wizard page appears. Click Finish to launch a troubleshooter to help resolve any problems you might be having with that hardware device.
After installing hardware, you should confirm the installation using the Device Manager.
You can do the following to start Device Manager:
Device Manager can also be launched from the Computer Management console. It is a snap-in located under System Tools.
This allows you to view the installed hardware, as shown in Figure 11.3.
Figure 11.3 Device Manager showing devices listed by type
Windows XP Professional uses icons in the Device Manager window to identify each installed hardware device. If Windows XP Professional does not have an icon for the device type, it displays a question mark.
Expand the device tree to locate the newly installed hardware device. The device icon indicates whether the hardware device is operating properly. You can use the information in Table 11.1 to determine the hardware status.
Table 11.1 Device Manager Hardware Status
Hardware is operating properly.
Stop sign on icon
Windows XP Professional disabled the hardware device because of hardware conflicts. To correct this, right-click the device icon and then click Properties. Set the hardware resources manually according to what is available in the system.
Exclamation point on icon
The hardware device is incorrectly configured or its drivers are missing.
To manually install hardware, first determine which hardware resource is required by the hardware device. Next, you must determine the available hardware resources. In some cases, you will have to change hardware resources. Finally, you might have to troubleshoot any problems you encounter.
When installing new hardware, you need to know what resources the hardware can use. You can reference the product documentation to determine the resources that a hardware device requires. Table 11.2 describes the resources that hardware devices use to communicate with an operating system.
Table 11.2 Hardware Device Resources
Hardware devices use interrupts to send messages. The microprocessor knows this as an interrupt request (IRQ). The microprocessor uses this information to determine which device needs its attention andthe type of attention that it needs. Windows XP Professional provides 16 IRQs, numbered 0 to 15, that are assigned to devices. For example, Windows XP Professional assigns IRQ 1 to the keyboard.
I/O ports are a section of memory that a hardware device uses to communicate with the operating system. When a microprocessor receives an IRQ, the operating system checks the I/O port address to retrieve additional information about what the hardware device wants it to do. An I/O port is represented as a hexadecimal number.
Direct memory access (DMA)
DMAs are channels that allow a hardware device, such as a floppy disk drive, to access memory directly, without interrupting the microprocessor. DMA channels speed up access to memory. Windows XP Professional has eight DMA channels, numbered 0 through 7.
Many hardware devices, such as a network interface card (NIC), use onboard memory or reserve system memory. This reserved memory is unavailable for use by other devices or Windows XP Professional.
After you determine which resources a hardware device requires, you can look for an available resource. Device Manager provides a list of all hardware resources and their availability, as shown in Figure 11.4.
Figure 11.4 Device Manager showing resources listed by connection
You can do the following to view the hardware resource lists:
The Device Manager displays the resources that are currently in use (for example, IRQs).
When you know which hardware resources are available, you can install the hardware manually with the Add Hardware Wizard.
If you select a hardware resource during manual installation, you might need to configure the hardware device so that it can use the resource. For example, for a network adapter to use IRQ 5, you might have to set a jumper on the adapter and configure Windows XP Professional so that it recognizes that the adapter now uses IRQ 5.
You might need to change hardware resource assignments. For example, a hardware device might require a specific resource presently in use by another device. You might also encounter two hardware devices requesting the same hardware resource, resulting in a conflict.
To change a resource setting, use the Resources tab in the device's Properties dialog box. You can use the following procedure to access the Resources tab:
When you change a hardware resource, print the content of Device Manager. This provides you with a record of the hardware configuration. If you encounter problems, you can use the printout to verify the hardware resource assignments.
From this point, follow the same procedures that you used to choose a hardware resource during a manual installation.
Changing the resource assignments for non-Plug and Play devices in Device Manager does not change the resources used by that device. You only use Device Manager to instruct the operating system on device configuration. To change the resources used by a non-Plug and Play device, consult the device documentation to see whether switches or jumpers must be configured on the device.
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 lesson. The answers are in Appendix A, "Questions and Answers."