The remote server returned an error: (407) Proxy Authentication Required in windows server 2003

Question

One of the .net solution which is built on framework 4, we are using this solution to generate some security token based on DefaultNetworkCredentials, i have registered this dll in register(regasm /codebase) and consuming this from classic asp application and its working fine in my local machine.

But when do same step in windows server 2003 and trying to access from IIS(classic asp is hosted in IIS) it is failing to take DefaultNetworkCredentials and i am getting below error,

"The remote server returned an error: (407) Proxy Authentication Required".

code in .net solution to get DefaultNetworkCredentials,

 var proxyObject = new WebProxy("Proxy", 80)
                    {
                         Credentials = CredentialCache.DefaultNetworkCredentials


                    };

Can anyone helpme on this, is this something settings in server or IIS?