To start your computer in safe mode, press F8 after you restart your computer. If the unknown device is no longer listed in Device Manager, it is likely that the unknown device is not hardware. Check the Startup folder If you suspect that a particular program is the cause of the unknown device, check the Startup folder on your computer to see which programs are configured to start when your computer starts. The Startup folder is in the following location on your hard disk, where C is the drive on which Windows is installed, and user profile is your user profile:.
Use the System Information tool The System Information tool can be useful when you have to determine the cause of an unknown device. To use the System Information tool to view a list of programs that start when your computer starts, follow these steps:. Expand Software Environment , and then double-click Startup Programs. A list of the programs that are configured to start when your computer starts is displayed.
Check the event log for errors that refer to any of these programs. If you find an event that is related to a program in this list, remove the program. Be aware that when a program creates an unknown device, it is not necessarily an indication that the program does not work, unless the program depends on that device to start.
To use the System Information tool to view a list of problem devices, follow these steps:. Expand Components , and then double-click Problem Devices. A list of the devices that are installed on your computer that may have a problem is displayed in the details pane, as follows:. The Device column lists the common name for the device, or the name of the device driver associated with it. The Error Code column lists the error code associated with this specific problem.
Frequently, the Device Manager error code helps determine what created the unknown device. For example, if your computer generates a 'Bad or missing device driver' error message, three types of entries may be listed under Problem Devices , depending on the device type:.
View the Setupapi. By default, the Setupapi. Sometimes the listed device name 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 typically occurs when a partial Plug and Play ID is available, and Device Manager interprets it as a serial device. This interpretation may 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 correctly. Be aware that merely removing the unknown device in Device Manager does not work if a software program is the cause of the unknown device.
You must remove the program and then restart your computer. If the unknown device is still listed in Device Manager after you restart your computer in safe mode, contact Microsoft Customer Support Services for help in removing the device. Remove hardware devices from your computer Remove hardware devices one at a time until the unknown device is no longer listed in Device Manager. Be aware that this method may be time-consuming and is not always reliable.
Determine whether the device driver is digitally signed When you install a device driver, and Windows detects that it is not digitally signed, you may receive a warning message and the option to cancel or continue the installation This message is displayed only if your computer is configured to display a warning message whenever an installation program tries to install a device driver without a digital signature. Note A device driver that is digitally signed can still be listed as an unknown device in Device Manager.
For more information about driver signing for Windows, visit the following Microsoft Web site:. You can block the installation of device drivers that do not contain a digital signature.
Use this approach when you want to prevent any deliberate attempts to destabilize the computer. To do this, follow these steps:. Click Start , click Run , type control sysdm. Under Drivers , click Driver Signing , and then click Block - Never install unsigned driver software. To view a list of device drivers installed on your computer that are not digitally signed, use either of the following methods:.
Error 0xef: The third-party INF does not contain digital signature information. Copying file C:documents and settings user name my documentsparallel port test driversepatapnt. An unsigned or incorrectly signed driver C:documents and settings user name my documentsparallel port test driversepatapnt.
Use the File Signature Verification tool The File Signature Verification tool lists all the unsigned drivers that are installed on your computer. It creates a Sigverif. Use any text editor for example, Notepad to view the file. To use the File Signature Verification tool to display a list of drivers that are not digitally signed, follow these steps:.
Click Advanced , click the Search tab, and then click Look for other files that are not digitally signed. Review the list, and then contact the driver manufacturer for information about how to obtain an updated driver that is digitally signed.
USB devices that are based on earlier versions of the USB specification may create ghost devices that appear when the device is connected, and then disappear when the device is disconnected. Also, the device may work fine, but may create a disassociated unknown device.
This is typically caused by firmware that is either outdated or configured incorrectly. In this case, contact the device manufacturer for updated firmware. A ghosted device can appear if you manually install a driver for a Plug and Play device that the computer has already detected and installed. You can resolve this issue by deleting the ghosted device.
For more information about how to use Device Manager to manage devices in Windows XP, click the following article numbers to view the articles in the Microsoft Knowledge Base:. The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.
The content in this article is for Windows Mobile Device Center which is no longer supported. The corresponding downloads have been removed from the Microsoft Download Center.
To access your phone on your PCs, use Your Phone application on your system. Windows Mobile Device Center offers device management and data synchronization between a Windows Mobile-based device and a computer. Download and install Windows Mobile Device Center 6. You can use Windows Mobile Device Center 6. To determine which Windows Mobile operating system you're using if your phone doesn't have a touch screen, click Start , click Settings , and then click About.
If your phone has a touch screen, tap Start , tap the System tab, and then tap About. To sync content to any of these devices, you must use a USB or serial cable, your computer's Internet connection, and File Explorer. Windows Mobile Device Center has a new, simplified partnership wizard and has improved partnership management.
The photo management feature helps you detect new photos on a Windows Mobile-based device. Then, this feature helps you tag the photos and import the photos to the Windows Vista Photo Gallery. You can use Microsoft Windows Media Player to synchronize music files and to shuffle music files on a Windows Mobile-based device.
A new device browsing experience lets you quickly browse files and folders. Additionally, you can open documents that are on a Windows Mobile-based device directly from a computer. You must use Microsoft Outlook , Outlook , or Office Outlook to sync your email, contacts, tasks, and notes from your computer.
Windows Mobile Device Center has a simple user interface that helps you quickly access important tasks and configure a Windows Mobile-based device. A1: First, make sure that your device is connected to the computer. A splash screen will be displayed when Windows Mobile Device Center detects your phone and starts. Use any of the following methods to determine whether an unknown device is being created by software:. Start your computer in safe mode Although not percent reliable, starting your computer in safe mode can be one of the easiest ways to determine whether the unknown device is created by software.
To start your computer in safe mode, press F8 after you restart your computer. If the unknown device is no longer listed in Device Manager, it is likely that the unknown device is not hardware. Check the Startup folder If you suspect that a particular program is the cause of the unknown device, check the Startup folder on your computer to see which programs are configured to start when your computer starts.
The Startup folder is in the following location on your hard disk, where C is the drive on which Windows is installed, and user profile is your user profile:.
Use the System Information tool The System Information tool can be useful when you have to determine the cause of an unknown device. To use the System Information tool to view a list of programs that start when your computer starts, follow these steps:. Click Start , click Run , type msinfo32, and then click OK.
Expand Software Environment , and then double-click Startup Programs. A list of the programs that are configured to start when your computer starts is displayed. Check the event log for errors that refer to any of these programs. If you find an event that is related to a program in this list, remove the program. Be aware that when a program creates an unknown device, it is not necessarily an indication that the program does not work, unless the program depends on that device to start.
To use the System Information tool to view a list of problem devices, follow these steps:. Expand Components , and then double-click Problem Devices. A list of the devices that are installed on your computer that may have a problem is displayed in the details pane, as follows:. The Device column lists the common name for the device, or the name of the device driver associated with it. The Error Code column lists the error code associated with this specific problem.
Frequently, the Device Manager error code helps determine what created the unknown device. For example, if your computer generates a "Bad or missing device driver" error message, three types of entries may be listed under Problem Devices , depending on the device type:.
View the Setupapi. By default, the Setupapi. Sometimes the listed device name 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 typically occurs when a partial Plug and Play ID is available, and Device Manager interprets it as a serial device.
This interpretation may 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 correctly. Be aware that merely removing the unknown device in Device Manager does not work if a software program is the cause of the unknown device. You must remove the program and then restart your computer.
If the unknown device is still listed in Device Manager after you restart your computer in safe mode, contact Microsoft Customer Support Services for help in removing the device. Remove hardware devices from your computer Remove hardware devices one at a time until the unknown device is no longer listed in Device Manager.
Be aware that this method may be time-consuming and is not always reliable. Determine whether the device driver is digitally signed When you install a device driver, and Windows detects that it is not digitally signed, you may receive a warning message and the option to cancel or continue the installation This message is displayed only if your computer is configured to display a warning message whenever an installation program tries to install a device driver without a digital signature.
Note A device driver that is digitally signed can still be listed as an unknown device in Device Manager. For more information about driver signing for Windows, visit the following Microsoft Web site:. You can block the installation of device drivers that do not contain a digital signature.
Use this approach when you want to prevent any deliberate attempts to destabilize the computer. To do this, follow these steps:. Click Start , click Run , type control sysdm.
Under Drivers , click Driver Signing , and then click Block - Never install unsigned driver software. To view a list of device drivers installed on your computer that are not digitally signed, use either of the following methods:. Error 0xef: The third-party INF does not contain digital signature information.
Use the File Signature Verification tool The File Signature Verification tool lists all the unsigned drivers that are installed on your computer.
It creates a Sigverif. Use any text editor for example, Notepad to view the file. To use the File Signature Verification tool to display a list of drivers that are not digitally signed, follow these steps:. Click Start , click Run , type sigverif, and then click OK. Click Advanced , click the Search tab, and then click Look for other files that are not digitally signed. Click to select the Include subfolders check box, and then click Browse.
Review the list, and then contact the driver manufacturer for information about how to obtain an updated driver that is digitally signed. USB devices that are based on earlier versions of the USB specification may create ghost devices that appear when the device is connected, and then disappear when the device is disconnected. Also, the device may work fine, but may create a disassociated unknown device. This is typically caused by firmware that is either outdated or configured incorrectly.
In this case, contact the device manufacturer for updated firmware. A ghosted device can appear if you manually install a driver for a Plug and Play device that the computer has already detected and installed.
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