On Windows systems, before you restart the Web Proxy Server 4.0.x instance, set the agent dll path in the system PATH variable. Otherwise, you might get a “Configuration initialization failed” error, indicating that an agent dll file could not be found.
The system PATH variable must include drive:installation-directory\web_agents\proxy40_agent\lib.
For example: c:\v30agents\web_agents\proxy40_agent\lib