IIS hijacks CORS Preflight OPTIONS request

Question

I am making a CORS POST request and setting the Content-Type header to json. This triggers a Preflight OPTIONS request to fire (this is good and expected)

This OPTIO

Answer 1

I tried all the mentioned posts but nothing worked for me, then i shifted my ASP.Net Web API 2 service to windows server 2012 (IIS 8.5) and same service worked without any changes. So issue was specific to IIS 7.5 on windows 7 machine.