If you ever need to list the user in a domain. For example Artinsoft.com this is code might be helpful
public static void Main()
{
var ctx = new PrincipalContext(ContextType.Domain,"Artinsoft",
"DC=artinsoft,DC=com");
UserPrincipal userPrin = new UserPrincipal(ctx);
userPrin.Name = "*";
var searcher = new System.DirectoryServices.AccountManagement.PrincipalSearcher();
searcher.QueryFilter = userPrin;
var results = searcher.FindAll();
foreach (Principal p in results)
{
Console.WriteLine("Name:{0},Account={1},DisplayName={2},Distinguish={3}",
p.Name,
p.SamAccountName,
p.DisplayName,
p.DistinguishedName);
}
}