donderdag 10 mei 2007

Device Manager Does Not Display Devices Not Currently Present

Article ID:241257
Last Review:March 1, 2007

Device Manager displays only non-Plug and Play devices, drivers, and printers when you click the Show hidden devices command on the View menu to enable it. Devices that are installed but are not currently connected to the computer (such as a Universal Serial Bus (USB) device or "ghosted" devices) are not displayed in Device Manager, even when you use the Show hidden devices command.

To work around this behavior and display phantom devices when you use the Show hidden devices command:
Click Start, point to Programs, point to Accessories, and then click Command Prompt.
At the command prompt, type the following lines, pressing ENTER after each line
set devmgr_show_nonpresent_devices=1cd\%SystemRoot%\System32start devmgmt.mscwhere %SystemRoot% is the folder in which Windows 2000 is installed.
Troubleshoot the devices and drivers in Device Manager, as required.NOTE: You must first select show hidden devices on the Device Manager View menu before you can see devices that are no longer present in the system.
When you are done troubleshooting, quit Device Manager, and then close the Command Prompt window. Closing the window clears the variable you set in step 2 and prevents ghosted devices from being displayed when you use the Show hidden devices command.NOTE: When you quit Device Manager and close the Command Prompt window, the set devmgr_show_nonpresent_devices=1 variable is turned off so you cannot see the phantom devices. An alternative approach, for developers or power users who need this feature enabled constantly, is to set this environment variable globally. To do so, perform the following steps:
Right-click My Computer.
Click Properties.
Click the Advanced tab.
Click the Environment Variables tab.
Set the variables in the System Variables box.NOTE: You should use this method only for troubleshooting or development purposes, to prevent users from accidentally uninstalling a required device that is not currently present (such as a USB device or docking station that is not currently connected to a laptop computer).

This behavior is by design.


In Device Manager, there are two types of hidden devices in addition to the typical devices that are displayed:

Typical hidden devices, which are not displayed (non-Plug and Play drivers, printers, and so on).

Phantom devices, which are not currently connected to the computer. NOTE: The method outlined in the "Workaround" section should be used only by Support Professionals to troubleshoot customer-related issues with devices and installed drivers.

Geen opmerkingen: