Windows XP [Electronic resources] : Visual Quickstart Guide, Second Edition نسخه متنی

Managing Device Drivers

Device Manager is a powerful tool that lets you inspect, manage, and troubleshoot drivers for the hardware already installed on your computer. It lists every device in or attached to your system in an Explorer-like tree (Figure 8.15 ).

Setting up User Accounts" in Chapter 16.

To open Device Manager:

Choose Start > Control Panel > Performance and Maintenance > System > Hardware tab > Device Manager.

or

Right-click My Computer (in the Start menu); then choose Properties > Hardware tab > Device Manager.

or

Choose Start > Run; type devmgmt.msc and then press Enter.

Tips

Choose View > Show Hidden Devices to display

legacy (nonPlug and Play) devices.

To expand all branches of the Device Manager tree, select the top-level (root) entry; then press * (on the numeric keypad).

Like any file, a device driver has properties that determine its behavior.

To show a device's properties:

In Device Manager, right-click the device; then choose Properties (refer to Figure 8.15).

or

Double-click the device's name.

The tabs of the Properties dialog box vary by device. The standard ones are:

General shows the name, type, physical location, and status of the device (Figure 8.16 ).

Advanced (if it appears) contains device-specific properties. A network adapter, for example, may have a connection-type property.

Driver shows information about the currently installed driver and has buttons that let you manage it (Figure 8.17 ).

Resources lists the system hardware resources (such as interrupts and memory range) that the device uses.

Tip

Some devices install their own Control Panel extensions, which let you view or change additional properties.

You can use Device Manager to install a driver that's newer than the current one. But newer doesn't always mean better or more stable. If a driver isn't broken, don't update it unless updating improves things.

To update a device driver:

1. In Device Manager, right-click the device whose driver you want to update; then choose Update Driver (refer to Figure 8.15).

2. Use the Hardware Update Wizard to install the new driver.

If Service Pack 2 is installed,

Figure 8.18, top appears as the first page. Select one of the Yes options to have Windows scour the Microsoft web site for an updated driver. Or select No if you already have a driver to install; then click Next to advance to

Figure 8.18, bottom . (Without SP2, this page appears first.) Select the second option, Install from a List or Specific location (Advanced), and point the wizard to the new driver's location.

The remaining steps are the same as those in the Found New Hardware and Add Hardware wizards, described earlier in this chapter.

Tip

Some devices have proprietary update programs that don't support the Hardware Update Wizard.

If a fresh driver causes more problems than it solves (not uncommon for unsigned drivers and prerelease drivers), the driver rollback feature lets you uninstall and replace it with the previous one.

To roll back a device driver:

In Device Manager, right-click the device whose driver you want to roll back; then choose Properties > Driver tab > Roll Back Driver (refer to Figure 8.17).

Tips

The rollback feature is available only if the driver has been updated since Windows was installed.

When you install a prerelease (beta ) driver, you're helping the software developer. Don't install a beta driver unless it fixes a flaw that's bugging you.

Troubleshooting Hardware

If you install and uninstall enough hardware on your system, you're going to have to deal with error messages and system conflicts. When trouble comes, the first step is to use Windows' built-in troubleshooters: Choose Start > Help and Support > Hardware > Fixing a Hardware Problem > Hardware Troubleshooter (under Fix a Problem). Use the wizardlike screens to try to resolve the problem.

No luck? Use Device Manager: Double-click a device (refer to Figure 8.15) to show its Properties dialog box and then click the General tab. If the device isn't working, the Device Status box shows an error message and code (refer to Figure 8.16). For an explanation of the problem and advice on how to fix it, go to http://support.microsoft.com/?kbid=125174, "Explanation of Error Codes Generated by Device Manager." Or click the Troubleshoot button for a device-specific troubleshooter.

Before you become aggressive, back up your drivers with DriverGuide Toolkit ($20 U.S.; www.driverguidetoolkit.com) or WinRet (free; http://winret.sourceforge.net).

You can remove a driver permanently and erase all the configuration settings for its device. Generally you uninstall a driver to reclaim system resources after you've removed hardware from your PC. But you can remove a troublesome driver completely, to scrap it or to reinstall it from scratch.

To uninstall a device:

In Device Manager, right-click the device whose driver you want to uninstall; then choose Uninstall (refer to Figure 8.15).

Tips

You can uninstall a Plug and Play device's driver only if the device is plugged in, because otherwise, the driver isn't in memory. To reinstall the driver without unplugging, in Device Manager, choose Action > Scan for Hardware Changes.

If Device Manager displays icons for duplicate devices (such as two mice), uninstall

both of them; then restart your PC. If you uninstall only one, Windows detects it again when you restart. Click No if Windows asks you to restart after you uninstall the first duplicate; restart manually after removing the second.

If you want to turn off a device without the hassle of removing it, you can disable it. Windows ignores a disabled device's existence and releases the system resources that it uses.

Generally you disable and enable devices to create hardware profiles (see the next section), but you also can use this technique to resolve device conflicts. If two devices are competing for the same resource, disable one of them; restart; and then see whether the other one starts working.

To disable a device:

In Device Manager, right-click the device that you want to disable; then choose Disable (refer to Figure 8.15).

A red X appears on the disabled device's icon (Figure 8.19).

Tips

To enable a disabled device, repeat the procedure. (The Disable command becomes the Enable command.)

A black-on-yellow exclamation mark (!) on the icon of a malfunctioning device (Figure 8.20) indicates a driver problem.

In Windows 9

x, conflicts were frequent because too many devices fought over scarce IRQs. An

IRQ, or

interrupt request, is a hardware line that a device uses to communicate with the CPU. Windows XP copes with this problem by letting devices share IRQs when possible (Figure 8.21).