The Diagnostic System Host (WdiSystemHost) service enables problem detection, troubleshooting, and resolution for Windows components. If this service is stopped, diagnostics cannot function. The Diagnostic System Host service is part of the Network Diagnostic Framework that is used to troubleshoot network connectivity issues.
This service is installed by default and its startup type is Manual. When the Diagnostic System Host service is started in its default configuration, it logs by on using the Local System account.
This service is not dependent on any other system service, nor is any service dependent on it.