title: Windows Authentication does not accept credentials
body: <p>I have an Identity Server (ASP.NET Core 2 with Identity Server 4 2.0.0) configured to use Kestrel and IISIntegration, with both Anonymous and Windows authentication enabled on launchSettings.json. I also configured IISOptions like this:</p>
  
  <pre><code>services.Configure&lt;IISOptions&gt;(iis =&gt;
  {
      iis.AutomaticAuthentication = false;
      iis.AuthenticationDisplayName = "Windows";
  });
  
  services.AddAuthentication();
  services.AddCors()
          .AddMvc();
  services.AddIdentityServer(); // with AspNetIdentity configured
  
  app.UseAuthentication()
      .UseIdentityServer()
      .UseStaticFiles()
      .UseCors(options =&gt; options.AllowAnyHeader().AllowAnyMethod().AllowAnyOrigin())
      .UseMvcWithDefaultRoute();
  </code></pre>
  
  <p>And I have this client (also ASP.NET Core 2 with both Windows and Anonymous authentication enabled, running on Kestrel with IISIntegration)</p>
  
  <pre><code>services.AddAuthentication(OpenIdConnectDefaults.AuthenticationScheme)
      .AddOpenIdConnect(config =&gt;
      {
          config.Authority = "http://localhost:5000";
          config.RequireHttpsMetadata = false;
          config.ClientId = "MyClientId";
          config.ClientSecret = "MyClientSecret";
          config.SaveTokens = true;
          config.GetClaimsFromUserInfoEndpoint = true;
      });
  
  services.AddMvc();
  </code></pre>
  
  <p>The Identity Server is running on <a href="http://localhost:5000" rel="nofollow noreferrer">http://localhost:5000</a> and the client on <a href="http://localhost:2040" rel="nofollow noreferrer">http://localhost:2040</a>. </p>
  
  <p>When I start the client it correctly presents the Identity Server's login screen, but upon clicking on Windows authentication only keeps asking for credentials. I've looked at the Output Window for both applications and there is no exception raising on either side. I have tried deploying the Identity Server to an IIS server (with Windows Authentication enabled and its pool running under NETWORK SERVICE) and the same behavior is reproduced.</p>