Fix IIS CGI Web Service Error

I have an issue with the IIS server. I am trying to run a DLL as a CGI web service. For some reason, the DLL web service returns an error when accessed. It doesn't come up with the xml information. If I try an executable file under the CGI folder, I can see the output of the exe file. This is the error I get: HTTP Error 500.0 - Internal Server Error The page cannot be displayed because an internal server error has occurred. A remote access will be provided to the server. The work is urgently needed, so apply only if you have the time. The person to take this task has to solve this issue and document how the problem was resolved.