Driver Education

How Your Operating System & Peripherals Communicate

First Published: Smart Computing Reference Series
Date Published: December 2003
By Kevin Savetz

Hooray, you've just connected a new printer, scanner, Web cam, or practically any other peripheral to your PC. But before you can start using that new gadget, you need to make sure there is a device driver installed in your system.

A device driver is software that acts as a bridge between the OS (operating system) and the peripheral. Although Windows knows in a general sense how to print and scan, for example, it does not know how to control every printer and scanner that is on the market. A device driver does know exactly how to talk to a specific printer or scanner because it was created specifically to work with that particular device. Once the driver is installed in your system, Windows can talk to the driver, and the driver can talk to the peripheral.

Not every piece of hardware requires a special driver, however, as Windows knows how to talk to generic hardware, such as your mouse, internal CD-ROM drives, and hard drives, without any help. Hardware that isn't so generic may need a driver after all. For example, an external CD burner or a mouse that has extra buttons would probably need a product-specific driver. The peripheral may work without a driver installed, but it probably won't deliver all of the peripheral's features.

In addition, a driver that's meant for one model of hardware probably won't work with another model, even if they're from the same manufacturer. Be sure to use the driver that was created for the exact model that you're using.

Install A Driver Via Windows

There are two ways to install a driver. First, you can install the driver yourself using a CD, floppy diskette, or downloadable installer, which contains the driver. Second, you can let Windows do it for you.

When Windows XP notices a new peripheral for the first time, for example, it pops up messages that alert you to its discovery. For internal peripherals, this usually occurs the first time you boot the computer with the new peripheral installed. For USB (Universal Serial Bus) and FireWire peripherals, this happens when you plug in and turn on that peripheral for the first time. If you have added a device for which Windows has built-in drivers, you'll quickly see a message that states, "The Device Is Ready To Use." There's no fuss, and you can go ahead and use the device.

If Windows needs to install a driver, it will automatically launch the Found New Hardware Wizard, which will attempt to

Use The Manufacturer's Installer

The alternative to the Found New Hardware Wizard is to use the installer that came with the hardware, which may be on a CD or is downloadable from the manufacturer's Web site.

Installing a driver from a CD is usually straightforward, although the procedure varies from one product to another. Typically, you will insert the CD, click Install, wait while the driver installs, and (perhaps) reboot the system. Similarly, if you download a driver from the manufacturer's Web site, you'll run the installer and follow the prompts.

Most of us don't like to read manuals, but be sure to read the section of the peripheral's manual that explains how and when to connect it to your computer for the first time. This is important because you may need to install the manufacturer's drivers from a CD before you connect the peripheral to the PC the first time. For some peripherals, the default Windows drivers will not work or will not deliver the hardware's full functionality. If you connect and turn on the device before installing the manufacturer's driver, the Add New Hardware Wizard will jump in and try to install Windows' default drivers.

Some power users only use CDs to install bundled software that accompanies hardware but don't install the drivers on those CDs. Instead, they download the

Drivers That Are Unsigned

When installing a driver, a window cautioning that the hardware hasn't passed "Windows Logo Testing" or that the hardware uses an "Unsigned Driver" may interrupt you. This is accompanied by a stern warning that reads "Continuing Your Installation Of This Software May Impair Or Destabilize The Correct Operation Of Your System." This dire-sounding admonition simply means that the driver doesn't have Microsoft's official stamp of approval for compatibility with your version of Windows. This can occur if you are trying to install a very old driver (one created for Windows 95, for example) that does not take into account changes made in later versions of Windows. If you think this may be the case, stop the installation and look to the manufacturer's Web site for a newer version of the driver.

The Unsigned Driver warning can also appear when installing drivers that will work perfectly with your OS but the manufacturer didn't get the official stamp of approval from Microsoft. If the product manual says the hardware is compatible with your OS, it's generally safe to click Continue and install the driver. (If it does crash your system, you can always use System Restore to revert back to a happier time. More on this later.)

In WinXP, you can turn off the warning or tell Windows never to install unsigned drivers. To do so, open the Control Panel and click Performance And Maintenance. Now click System, click the Hardware tab, and click the Driver Signing button. Now click the Block option.

Update Drivers

Like other software, drivers are updated occasionally to fix bugs or add new features. Microsoft's Windows Update Web site delivers some driver updates ( For other updates, you need to visit the Web site of the peripheral's manufacturer to download newer drivers.

If you are having a problem with a hardware device, checking for a new version of the hardware's driver is the first thing to try. On the other hand, if you notice that a new driver is available but your equipment is working fine, you may want to think twice before installing it. After all, why mess with something that works? Most manufacturers release a "change log" with each driver that explains what's new in that version. Read that document first to decide if you really need to upgrade.

To find out what version of a driver you're currently running, open the Control Panel in WinXP, click Performance And Maintenance, and then System. Click the Hardware tab and the Device Manager button. Find the peripheral in the Device Manager list, double-click its icon, and then click the Driver tab. You will see the driver's version number and date. Buttons located here will let you uninstall the driver, update the driver, or revert to an older version. This last option is handy if you've upgraded a driver and regret the change.

Resolve Driver Conflicts

With so many drivers installed on a system, all trying to talk to Windows, conflicts do occasionally arise. A driver conflict can cause crashes or prevent a peripheral from working properly. Conflicts can also be difficult to track down. For example, there may be two or more drivers that aren't playing nicely or a single buggy driver that's causing a problem.

If a problem crops up soon after you've installed a new driver, chances are the driver is the culprit. First, uninstall the driver. For many drivers, you do this by opening Control Panel, clicking Add Or Remove Programs, selecting the name of the hardware driver, and clicking the Add/Remove button. You can remove other drivers using the Device Manager. Open the Control Panel, click Performance And Maintenance, and then System. Click the Hardware tab and then click the Device Manager button. Find the peripheral in the Device Manager list, double-click its icon, click the Driver tab, and then click Uninstall.

In addition, the manufacturer may have released a new version of the driver that corrects the problem you're experiencing. Check the support section of the manufacturer's Web site for a new driver version. If that doesn't help, you may need to contact the manufacturer's technical support team.

If the problem persists and you're confident the issue is driver-related, try using WinXP's System Restore, which returns your PC to the state in which it was functioning at an earlier time. For example, you can restore the system back to the day before you installed those pesky drivers, with your documents and email still intact. In WinXP, from the Control Panel, click Performance And Maintenance, and then click System Restore.

Licensed To Drive

Device drivers are the invisible link between your OS and the hardware attached to it. You don't have to think about them much; most of the time you can install them and forget about them. But the next time you bring a new piece of hardware home, don't forget about the driver. Follow the manufacturer's instructions for installing it and enjoy your new peripheral.

Reprinted with permission from Smart Computing magazine.

Articles by Kevin Savetz