How to Troubleshoot Unknown Devices Listed in Device Manager

• Microsoft Windows 2000 Advanced Server
• Microsoft Windows 2000 Datacenter Server
• Microsoft Windows 2000 Professional
• Microsoft Windows 2000 Server

SUMMARY

When you view device information on your Windows 2000-based computer using Device Manager, you may see an unknown device listed next to a yellow question mark. Determining the cause of this unknown device can be difficult, because there are few indications of what could be creating it. This article describes the possible causes of an unknown device being listed in Device Manager.

MORE INFORMATION

The most common reasons Device Manager may list a device as unknown are:

The Device Does Not Have a Device Driver

You Are Using a Windows 98/95 Device Driver

Unrecognized Device ID

Faulty Hardware or Firmware

Virtual Device Created with Software

• While not 100 percent reliable, starting your Windows 2000-based computer in safe mode can be one of the easiest ways of determining if the unknown device is being created by software. When starting your Windows 2000-based computer, press F8, select Safe Mode, and then press ENTER. If the unknown device is no longer listed in Device Manager, then it is likely that the unknown device is not hardware.



• If you suspect a particular software program may be creating the unknown device, check the Startup folder on your Windows 2000-based computer to see what programs are configured to start at boot. Also, checking the menu bar can give you an indication as to what programs are automatically started, however, remember that some programs that may be configured to start at boot do not appear in the Startup folder.



• The Windows 2000 System Information Tool can be useful in diagnosing the cause of an unknown device. To run the System Information Tool:
  
  
  1. Click Start, point to Programs, point to Administrative Tools, and then click Computer Management.
  
  
  
  2. On the Computer Management dialog box, click the System Information folder, double-click the Software Environment folder, and then double-click the Startup Programs folder.
  
  
  
  3. A comprehensive list of every program configured to start at boot is displayed.
  
  
  
  You should then check the event log for errors relating to any of these programs to see if there is one that is not working properly. If you find a related event, uninstall the associated program. Note that the fact that a program is creating an unknown device is not an indication that the program does not work, unless the program depends on the device to start the associated program.



• You can view each component in your Windows 2000-based computer, including the drivers needed to make the components work. To view the components installed on your Windows 2000-based computer:
  
  
  1. Click Start, point to Programs, point to Administrative Tools, and then click Computer Management.
  
  
  
  2. In the Computer Management dialog box, double-click System Tools.
  
  
  
  3. Double-click System Information, and then double-click the Components folder.
  
  
  



• Check the Problem Devices folder, located under the Components folder.
  
  NOTE: Follow the steps on the previous method to view the Components folder.
  
  The following columns are listed:
  
  
  • The Device column lists the common name for the device, or the name of the device driver associated with it.
  
  
  
  • The PnP Device ID column lists device IDs such as Peripheral Component Interconnect (PCI) ID, Industry Standard Architecture (ISA) ID, an ID for some other bus type, or an unknown type.
  
  
  
  • The Error Code column lists the error code associated with this specific problem. In many situations, the Device Manager error code helps determine what created the unknown device. For example, if your Windows 2000-based computer generates a "Bad or missing device driver" error message, three types of entries may be listed in the Problem Devices folder, depending on the device type:
    
    
    • PCI PnP Device ID:
      
      Device Name | PCI\VEN_00000&DEV_0000&SUBSYS_00000000&REV_00\0&0000 | Error code
    
    
    
    • ISA PnP ID:
      
      Device Name | ?\PNP0000\0
    
    
    
    • Bad or Incompatible Device Driver:
      
      Device Name | ROOT\UNKNOWN\0000
    
    
    
  
  
  



• Information listed in the Setupapi.log file can be helpful in identifying what may have created the unknown device, as long as the device has a meaningful name. Sometimes the device name listed can be misleading. For example, a device may be listed as a serial device in Device Manager, when in reality it is not related to a serial port. This usually occurs when a partial Plug and Play ID is available, and Device Manager interprets it as a serial device. This interpretation can occur because of a compatible ID specified by the device. Again, this can be corrected by locating the startup program that may not be behaving properly.
  
  Note that simply removing the unknown device in Device Manager does work if a software program is creating the unknown device. You must uninstall the program that creates it, and then restart your Windows 2000-based computer. Also, if the unknown device does is still listed after you restart your Windows 2000-based computer in safe mode, contact Microsoft Technical Support for assistance in removing the device.
  
  

Hardware Devices

• Remove hardware devices from your Windows 2000-based computer one at a time until the unknown device is no longer listed in Device Manager. Note that this method may be slow, and is not always reliable.



• Check if the device driver is digitally signed. If during the device driver installation, Windows 2000 detects that a device driver is not digitally signed, the following error message is generated:

  Not Digitally Signed

  Note that a device driver that has been digitally signed could still be listed as an unknown device in Device Manager. Also note that the user may not see this error message if it has been disabled.
  
  NOTE: Information about digitally signing device drivers is available at the following Microsoft Web site, and by using the Device Driver Kit (DDK) tool:

  http://www.microsoft.com/ddk/

1. Click Start, point to Settings, and then click Control Panel.



2. Double-click System, and then click the Hardware tab.



3. Click Driver Signing, and then click Block - Prevent installation of unsigned files.



4. Click OK, and then click OK.

• View the Setupapi.log file for entries resembling the following entries:

  The file (D:\WINNT\inf\ntapm.inf) is not digitally signed, ignoring driver date.

  Installing section epatapi_inst from d:\documents and settings\user name\my documents\parallel port test drivers\epatapnt.inf An unsigned or incorrectly signed driver (d:\documents and settings\user name\my documents\parallel port test drivers\epatapnt.inf) was installed for Parallel ATAPI Adapter.. Error 0xe000022f: The third-party INF does not contain digital signature information. Copying file d:\documents and settings\user name\my documents\parallel port test drivers\epatapnt.mpd to D:\WINNT\System32\DRIVERS\epatapnt.mpd. An unsigned or incorrectly signed driver (d:\documents and settings\user name\my documents\parallel port test drivers\epatapnt.mpd) was installed for Parallel ATAPI Adapter.. Error 0xe000022f: The third-party INF does not contain digital signature information.

  where user name is a user name.



• Use the Sigverif.exe tool, which permits you to create a log file listing all of the unsigned drivers installed on your Windows 2000-based computer. The Sigverif.txt log file created by the Sigverif.exe tool is located in the %SystemRoot% folder of your Windows 2000-based computer, and can be viewed by using a text editor (such as Notepad). To run the Sigverif.exe tool:
  
  
  1. Click Start, click Run, type sigverif, and then click OK.
  
  
  
  2. Click Advanced, and then click Look for other files that are not digitally signed under the Search tab.
  
  
  
  3. Click to select the Include subfolders check box, and then click Browse.
  
  
  
  4. Locate and then click the %SystemRoot%\System32\Drivers folder, click OK, and then click Start.
  
  
  
  You may experience a delay while your computer compiles a comprehensive list of unsigned drivers. Check the list of unsigned drivers, and then check if the driver manufacturer has an updated driver that is digitally signed.

Additional query words: devmgr firewire

Keywords : kb3rdparty kberrmsg kbhw kbtool kbtshoot
Version : WINDOWS:2000
Platform : WINDOWS
Issue type : kbhowto