IIS + Windows Authentication + Web service .NET = HTTP Error 401.1 - Unauthorized

i have big problem.I want to use the web services with Windwos Integrated Authentication and no Anonymous Authentication.

I publish my service (asmx page) on the server. So when i try to access it with Network Credential as show below, 开发者_Python百科i receive HTTP Error 401.1 - Unauthorized.

My_WS.WSClass ws= new My_WS.WSClass();
ws.Credentials = new NetworkCredential("username", "password","domain");
ws.PreAuthenticate = true;
ws.callMethod(Parameter);

On IIS 7 i've enabled only Windows authentication, and my application pool Identity is "Network Service".

If i try my service with anonymous authentication it works.

Any suggestion ?

Thanx