Device Installation

In Windows XP Professional, how you install a device depends on whether the device and the computer are Plug and Play. When installing Plug and Play devices, Windows XP Professional detects and configures the device with little or no user intervention. Device driver installation also requires little user involvement because Windows XP Professional uses driver-ranking schemes and driver search location policies, among other features, to determine which drivers are loaded.

Installing a Device in Windows XP Professional

Windows XP Professional Setup performs an inventory of all devices on the computer and records the information about those devices in the registry. Setup gets configuration information for system devices from the .inf file associated with each device and, for Plug and Play devices, from the device itself.

When a new device is installed, Windows XP Professional uses the device s Plug and Play ID to search Windows XP Professional .inf files for an entry for that device. Windows XP Professional uses this information to create an entry for the device under the Hkey_Local_Machine subtree in the registry, and copies the drivers needed. Registry entries are then copied from the .inf file to the registry entry for the driver.

When you install a new device, rely first on Plug and Play to detect and configure it. How you install hardware depends on the type of device:

• For Plug and Play external devices, plug in the device.

• For Plug and Play internal devices, turn the computer off and install the device according to the manufacturer s documentation. You can, however, typically insert and remove PC Card, CardBus, and other Plug and Play devices without turning the computer off.

• For PCI and ISA Plug and Play cards, turn the computer off, and then install the device. When you restart the computer, Windows XP Professional detects the device and starts the Plug and Play installation procedures.

• For non Plug and Play devices, turn the computer off, and then install the device. When you restart the computer, run the Add Hardware wizard and let Windows XP Professional detect the device. This requires administrator permissions. If Windows XP Professional cannot detect the device, you might need to manually configure it. Consult the hardware vendor s documentation if this is necessary.

  Note 

  Whenever possible, use Plug and Play devices even in computers that do not have an ACPI BIOS in order to make available any additional Plug and Play functionality.

Installing Drivers

Many device drivers are installed with no user intervention. For example, when you plug in a USB mouse device, the drivers are automatically detected and installed.

Drivers are installed without user intervention if certain conditions are met:

• Installing the driver does not require showing a user interface.

• The driver package contains all files needed to complete the installation.

• The driver package is available on the system in the Driver.cab file, or was previously installed.

• The driver package is digitally signed.

• No errors occur during installation.

If any of these conditions is not met, the device installation restarts and the user might need to respond to dialog boxes or messages. Manual installation of a driver requires administrator permissions.

Note 

Drivers that support features specific to Windows XP Professional are not compatible with Microsoft Windows 98 or Microsoft Windows Millennium Edition (Me).

Windows XP Professional determines which device driver to load for a device by using these features:

• Driver-ranking schemes

• Driver search location policies

• Windows Driver Protection

• Windows Update

For more information about device drivers, including driver-ranking schemes, Windows Driver Protection, driver search location policy, and Windows Update, see Device Drivers earlier in this chapter.