A secure WSD device may not work correctly on a computer that is running Windows 7


When you try to use a secure Web Services on Devices (WSD) device with a computer that is running Windows 7, you may encounter one or more of the following problems:
  • You cannot install or use a secure WSD device.
  • A secure WSD device that worked does not work after its certificate is updated.


This problem occurs because the Function Discovery Provider Host (fdPHost) service cannot access certificates that are installed or updated after the fdPHost service was started.

This problem affects device certificates and root certificates that have a trust chain to the device. If either of these certificates is installed or updated after the fdPHost service was started, the device seems to be unavailable or offline. However, this problem occurs with all Web Services on Devices (DPWS) devices that implement security.

For more information about certificates that a secure WSD device requires, see the "More information" section.


To work around this problem, restart the fdPHost service.
Note After you restart the fdPHost service, you may also have to restart any affected third-party services that use fdPHost for discovering or for using WSD devices.
To restart the fdPHost service, use one of the following methods.

Method 1

  1. Click StartStart button , type services.msc in the Start Search box, and then press ENTER.
  2. In the list of services, right-click Function Discovery Provider Host, and then click Restart.

Method 2

  1. Click StartStart button , click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.
    User Account Control permission If you are prompted for an administrator password or for confirmation, type the password, or click Yes.
  2. At the command prompt, type the following command to stop the fdPHost service, and then press ENTER:
    net stop fdphost
  3. After the fdPHost service is stopped, type the following command to restart the fdPHost service, and then press ENTER:
    net start fdphost

More Information


A Windows-based client and a secure WSD device that communicate over a security channel use certificates when they establish a connection.

A secure WSD device must meet the following certificate requirement:
  • The secure device must have an X.509 public key certificate.
  • The Enhanced Key Usage section of the certificate must contain the Server Authentication ( object identifier (also known as OID).
A Windows-based WSD client must be configured correctly to use certificates before it interacts with a secure WSD device.

For more information about secure WSD device certificates and Windows-based client configuration, visit the following Microsoft Web sites:

รหัสบทความ: 973560 - การตรวจสอบครั้งสุดท้าย: 5 ส.ค. 2009 - ฉบับแก้ไข: 1