SetupSVC is a tool to extract registry settings for running WebLink, Monitor or LinkOPC as a service. The tool automatically creates the INI files that the services read to initialize themselves with correct IP address, port #, HostID etc.
DON'T FORGET! You have to first get the software working correctly while running as an application, then you can use this tool to automatically create the INI files. Once you have the correct INI files you can follow the instructions for setting up services.
Here's a Knowledge Base article with instructions for setting WebLink and OPC Server as services