Diagnostic Service Host (WdiServiceHost) Defaults in Windows 7

The Diagnostic Service Host is used by the Diagnostic Policy Service to host diagnostics that need to run in a Local Service context. If this service is stopped, any diagnostics that depend on it will no longer function.

Default Settings

Startup type:Manual
Display name:Diagnostic Service Host
Service name:WdiServiceHost
Service type:share
Error control:normal
Object:NT AUTHORITY\LocalService
Path:%SystemRoot%\System32\svchost.exe -k LocalService
File:%SystemRoot%\system32\wdi.dll
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WdiServiceHost
Privileges:
  • SeChangeNotifyPrivilege
  • SeImpersonatePrivilege
  • SeSystemProfilePrivilege

Default Behavior

Diagnostic Service Host is a Win32 service. In Windows 7 it won't be started if the user doesn't start it. When the Diagnostic Service Host is started, it is running as NT AUTHORITY\LocalService in a shared process of svchost.exe. Other system components, such as drivers and services, may run in the same process. If Diagnostic Service Host fails to start, Windows 7 attempts to write the failure details into Event Log. Then Windows 7 startup should proceed and the user should be notified that the WdiServiceHost service is not running because of the error.

Restore Default Startup Configuration for Diagnostic Service Host

1. Select your Windows 7 edition and service pack, and then click Download.

2. Save the Win7_WdiServiceHost_Service_Startup.cmd file to a local storage device.

3. Run the saved file as an administrator.

4. Restart the computer.

The WdiServiceHost service is using the wdi.dll file that is located in the %WinDir%\system32 folder. If the file is changed, damaged or deleted, you can restore its original version from Windows 7 installation media.