Prompt user for username/password with windows authentication for a request to another server

Hello, Is there a way to perform a get request for a ressource on a different server needing windows authentication and having the user automaticly being  prompted for his credentials  

WebClient c = new WebClient()

//c.Credentials = CredentialCache.DefaultNetworkCredentials;

c.DownloadData(new Uri("http://myothersevrer.com/adin/test.txt"));

So instead of supplying Credentials in the backend I would like the user to be automaticly prompted for his Credentials. The 2 are not related....

Alex