Device Management

For Plug and Play devices, there are no true default settings. Instead, Windows 2000 Professional identifies devices and their resource requests and arbitrates requests among them. If no device requests the same resources as another device, their settings do not change. If another device requests the same resources, the settings might change to accommodate the request. Consequently, you must never change resource settings for a Plug and Play device unless absolutely necessary. Doing so fixes its settings, making it impossible for Windows 2000 Professional to grant another devices request to use that resource. Changed resource settings can be brought back to the original values by checking the Use automatic settings box under the Resources tab of the Device PropertiesPage in Device Manager. See the procedure To change a devices resource settings using Device Manager later in this section.

Note

Windows 2000 Professional might allocate a single resource to more than one device.

Legacy devices that have fixed resource settings are discovered either during Windows Setup or through the Add/Remove Hardware wizard.

Certain circumstances might require users to change resource settings after Windows 2000 Professional has configured a device. For example, Windows 2000 Professional might not be able to configure one device without creating conflicts with another device. In such a case, a message usually appears to explain what is happening and what you can do about the problem — turn off a device to make room for the new device, disable the new device, or reconfigure a legacy device to make room for the new device.

For more information about troubleshooting problems with devices, see Troubleshooting Device Management later in this chapter and Troubleshooting Tools and Strategies in this book.

Use Device Manager instead of a registry editor to manually change a devices configuration. Before making any changes to your device configuration, back up your registry so that you can restore your original settings in the event of any problems.

Caution

Do not use a registry editor to edit the registry directly unless you have no alternative. The registry editors bypass the standard safeguards provided by administrative tools. These safeguards prevent you from entering conflicting settings or settings that are likely to degrade performance or damage your system. Editing the registry directly can have serious, unexpected consequences that can prevent the system from starting and require that you reinstall Windows 2000. To configure or customize Windows 2000, use the programs in Control Panel or Microsoft Management Console (MMC) whenever possible.

If you need or want to resolve device conflicts manually, you can use Device Manager and try the following strategies:

• Identify a free resource, and assign the device to use that resource.

• Disable a conflicting Plug and Play device to free its resources.

• Disable a legacy device to free its resources, by removing the legacy device card and not loading the device drivers.

• Rearrange resources used by another device or devices to free resources needed by the device with a conflict.

• After turning off and unplugging your computer, change jumpers on your hardware to match the new settings.

Caution

Changing default settings using either Device Manager or a registry editor can cause conflicts that make one or more devices unavailable on the system.

To use Device Manager

1. In Control Panel, double-click System , click the Hardware tab, and then click the Device Manager button.

2. Double-click the device type in the list to display the devices of that type on your computer.

3. Double-click the device that you want to configure, or select the device, and then click Properties to view or change its settings.

You can use Device Manager to print reports about system settings, including the following:

• System summary

• Selected class or device

• All devices and system summary

To print a report about system settings

1. In Device Manager, click Print .

2. In the Print dialog box, click the type of report you want.

The following procedure explains how to change a devices resource settings using Device Manager. Change resource settings only if absolutely necessary. Changing resource settings can cause conflicts and can cause you to lose Plug and Play functionality. Also, before changing resource settings, make sure that your problem is a resource conflict and not a missing driver.

To change a devices resource settings using Device Manager

1. In Device Manager, expand the device class to show the available devices.

2. Click a device, and then click Properties . The Device Properties dialog box is displayed.

3. Click the Resources tab. Notice that the Conflicting device list shows any conflicting values for resources used by other devices.

4. In the Resource type list, select the setting you want to change. Make sure the Use automatic settings box is unchecked.

5. Click Change Setting . The dialog box for editing the particular setting is displayed.
   If there is a conflict with another device, a message is displayed in the Conflict Information field.
   
   Note
   When you click Change Setting , you might see an error message saying, This resource setting cannot be modified. In this case, you need to choose a different basic configuration until you find one that allows you to change resource settings.

6. Choose a setting that does not conflict with any other devices, and then click OK .

7. Restart Windows 2000 Professional. Then verify that the settings are correct for the device.

Note

Many legacy devices have jumpers or switches that set the IRQ, DMA, and I/O addresses. If you change these settings in Device Manager, you must also change the settings on the device to match them.