The RPC server is unavailable

Rpc Server Unavailable on Windows from missing or incorrect environment variables is more complex than on Linux because Windows has multiple environment variable scopes (system, user, process) and different inheritance rules for processes launched through different mechanisms. System environment variables are set in Control Panel → System → Advanced → Environment Variables and require a system restart or logoff to take effect for GUI applications. User environment variables apply only to the current user and take precedence over system variables with the same name. Process variables set in a terminal session (cmd or PowerShell) are inherited by child processes but do not persist after the session ends. For Windows Services, environment variables are configured per service in the Registry under HKLMSYSTEMCurrentControlSetServices<service>Environment. PowerShell's $env:VARIABLE syntax accesses environment variables within the session; [System.Environment]::SetEnvironmentVariable() persists them. When Rpc Server Unavailable appears intermittently on Windows, check whether the issue correlates with service restarts — services do not pick up environment variable changes until restarted.