Dealing with Devices

Like most administrators, whenever I needed to solve a hardware problem in Windows NT, I wished I could use the Windows 9x Device Manager. This tool makes viewing and configuring device settings a snap and also simplifies troubleshooting hardware problems that result from settings conflicts or incorrect drivers.

I was delighted to find Device Manager in Windows 2000. If you have nothing but Plug and Play (PnP) devices throughout your Win2K system, you won't need to configure or troubleshoot hardware and you don't need to read this article. However, I suspect I could fit around my dining room table all the enterprise systems administrators to whom that statement applies. Using Device Manager, you can make configuration changes, install and uninstall devices, and generally resolve problems without much trouble.

Accessing Device Manager
Device Manager is a Microsoft Management Console (MMC) snap-in. To open Device Manager, you can use one of the following methods:

• Right-click My Computer and choose Manage to open the local MMC Computer Management console. Select the Device Manager object under Computer Management, System Tools to display Device Manager in the console's right pane, as Figure 1, page 130, shows.
• Right-click My Computer, and choose Properties to open the System Properties dialog box. Move to the Hardware tab, and click Device Manager to open Device Manager as a standalone console, which Figure 2, page 130, shows.
• Type

devmgmt.msc

from the Run command or the command prompt to open Device Manager as a standalone console.

Viewing Devices
By default, Device Manager displays devices alphabetically by type (i.e., class). Expand each type listing to reveal the devices in that type. Usually, no classes are expanded when you open Device Manager. However, if a device has a problem, its class is expanded and the device's listing displays a yellow exclamation point.

To examine or manipulate a device, expand its class and double-click the device listing to open its Properties dialog box. The dialog box always includes a General tab (which Figure 3, page 130, shows) that reports the device's current status, and a Driver tab, on which you can view detailed information about the device's driver as well as update the driver. Most devices also provide a Resources tab, which shows the resources that the device uses.

By default, Device Manager hides several devices; to view them, choose View, Show hidden devices from the console menu. On most systems, this action results in the display of a Non-Plug and Play Drivers device class, which expands to a list of drivers that support system services. Other drivers might also appear, depending on the types of installed devices and drivers on the computer. For example, by default, expanding the Network adapters class shows only the physical NIC or NICs, but when you expose hidden devices you'll also see such drivers as the WAN miniport drivers for IP, PPTP, and other protocols.

You can rearrange the order in which Device Manager displays devices. From the View menu, choose one of the following options:

• Devices by connection sorts the list according to the device's connection (e.g., COM2, system board).
• Resources by type sorts the list according to the resources attached to each type of
  device.
• Resources by connection sorts the list according to the resources that each connection type uses.

These views are handy for figuring out conflict problems. For example, either of the last two options provides an easy way to check IRQ assignments. Simply choose one of those views and expand the Interrupt request (IRQ) listing, as Figure 4 shows.

Configuring Devices
You can also use Device Manager to configure devices—for example, to change resource settings or to change or update drivers. (Not all devices offer a full range of configuration options; some devices are locked in to their settings.) And you can use Device Manager to enable or disable a device, which often provides a temporary cure for a resource conflict. (Again, not all devices offer these options—hard disks are a prime example.)

Changing resources. To change resources for a device, go to the Resources tab on the device's Properties dialog box. Select the resource you want to modify, clear the Use automatic settings check box, and click Change Setting. An appropriate dialog box opens. For example, when you select Interrupt Request, the Edit Interrupt Request dialog box, which Figure 5 shows, appears. Use the up and down arrows to the right of the Value text box to select a new setting. (You can manually enter a new setting, but the Value box has an advantage—it offers only valid choices.) As you select settings, the dialog box displays messages about conflicts, either stating that no conflicts exist or warning you that the setting conflicts with another device's setting.

Updating drivers. To update device drivers, go to the Driver tab and click Update Driver. The Upgrade Device Driver Wizard opens and walks you through the process. You can install drivers from a CD-ROM, 3.5" disk, local file, or network share point.

Disabling devices. You can disable a device, thus freeing the resources the device had been using. You can use this feature to troubleshoot resource-allocation problems; disabling a device lets you determine whether another device (which might have a resource conflict with the disabled device) works properly. Another common practice is to disable a device for a specific hardware profile. Laptop computers are the usual targets for hardware profiles, which let users choose to boot to a docking station. (Hardware profiles, which you create and configure from the System Properties dialog box's Hardware tab, are only necessary for non-PnP devices.)

Disabling a device doesn't remove it from Device Manager or remove the device's settings from the registry. The process simply makes the device unavailable and frees the resources it was using. After you disable a device, a red X appears atop the device's icon in Device Manager. To reenable the device, open the device's Properties dialog box and click Enable Device.