3.2.2 Hardware Attributes

• Installing Drivers

• Changing a Driver's Configuration

Installing Drivers

As previously discussed, each device must have a corresponding driver in the operating system to manage the commands, the transfer of data, and the error conditions that occur. Each operating system specifies an interface that a device driver must utilize. This means that for any particular device, it must have a corresponding driver for the operating system where it is intended to be used in order to be functional. Even versions of the same operating system may use an interface requiring a different driver. Also, a similar but different product from the same company will most likely require its own driver, because of some minor or major changes in how the device interacts with the software.

Drivers are supplied either with the operating system's distribution files, or individually from the manufacturer of the hardware device. At the time of a release of an operating system such as Windows, many of the most popular and well-known devices (printers, modems, scanners) will be tested and included with the release. However, less well-known brands or hardware products released later than the operating system will not be included. That is why each hardware device usually has an accompanying floppy or CD containing drivers for most of the operating systems available in the marketplace. If provided, a driver that comes packaged with a hardware device is always better to use than one that came with the operating system, since the driver packaged with the device is probably a more recent update containing better functionality, while correcting known errors.

The driver that accompanies a hardware device should allow you to use the device adequately. However, since products are shipped many months in advance of your purchase, there is high likelihood that more reported problems are corrected in the latest version of the driver on the company's Web site. Always check the company's Web site to see if a more recent version exists.

When you are installing a new hardware device under Windows, it most likely will be detected after a boot by the Plug and Play (PnP) control mechanism. If the device supports PnP, Windows should inform you that it found a new device and should ask you for the location of the driver. The driver can either be part of the Windows distribution itself (requiring you to use the Windows CD), a floppy, a CD, or a folder on the hard disk where you previously downloaded the driver from the Internet. If an appropriate driver is not found, Windows will be unable to use the device.

If you install a device and Windows does not recognize it, you must use the Add New Hardware wizard to install the device driver and have it recognized under Windows. This wizard allows you to have Windows search again for the device or for you to specify the device. There are a number of steps involved with manual installation, and the wizard attempts to lead you through entering the appropriate information. If you update a device driver, there is an "update button" associated with each device for you to perform this function manually. The process is similar to installing a driver for the first time, and the appropriate files must be on a disk to complete the update.