Diagnostic System Host - Windows 7 Service
The Diagnostic System Host is used by the Diagnostic Policy Service to host diagnostics that need to run in a Local System context. If this service is stopped, any diagnostics that depend on it will no longer function.
This service also exists in Windows 10, 11, 8 and Vista.
Startup Type
| Windows 7 edition | without SP | SP1 |
|---|---|---|
| Starter | Manual | Manual |
| Home Basic | Manual | Manual |
| Home Premium | Manual | Manual |
| Professional | Manual | Manual |
| Ultimate | Manual | Manual |
| Enterprise | Manual | Manual |
Default Properties
| Display name: | Diagnostic System Host |
| Service name: | WdiSystemHost |
| Type: | share |
| Path: | %WinDir%\System32\svchost.exe -k LocalSystemNetworkRestricted |
| File: | %WinDir%\system32\wdi.dll |
| Error control: | normal |
| Object: | LocalSystem |
| Privileges: |
|
Default Behavior
The Diagnostic System Host service runs as LocalSystem in a shared process. It shares the executable file with other services. If the Diagnostic System Host fails to load or initialize, the error is recorded into the Event Log. Windows 7 startup should proceed, but a message box is displayed informing you that the WdiSystemHost service has failed to start.
Restore Default Startup Type of Diagnostic System Host
Automated Restore
1. Select your Windows 7 edition and Service Pack, and then click on the Download button below.
2. Save the RestoreDiagnosticSystemHostWindows7.bat file to any folder on your hard drive.
3. Right-click the downloaded batch file and select Run as administrator.
4. Restart the computer to save changes.
Note. Make sure that the wdi.dll file exists in the %WinDir%\system32 folder. If this file is missing you can try to restore it from your Windows 7 installation media.