How to find Microsoft account linked to Windows login?

Question

I'm trying to add a feature in my C# app that looks up the email address associated with the Windows login, but I can not find anything on this!

The closest thing I found was it being listed in the Registry @ "HKEY_CURRENT_USER\Software\Microsoft\IdentityCRL" for one person, but not on any of my machines.

I've also tried "System.DirectoryServices.AccountManagement.UserPrincipal.Current.EmailAddress" but it returns nothing.

Has anyone ever had to look this up programmatically before? If so, any advice?

Answer 1

Interesting question. It got me looking around. This is what I got so far from a C# WinApp project. Under a Microsoft login account, I got it to display the "UserName" property that had my associated email address. Under a regular local account, it returned nothing. Run with it. Good luck.

using System;
using System.Linq.Expressions;
using System.Windows;
using System.Windows.Forms;

namespace WindowsAuthenticationProbing
{
    class Program
    {
        static void Main(string[] args)
        {
            //interesting to look at, but does not reveal the associated Windows login email
            var myIdentity = System.Security.Principal.WindowsIdentity.GetCurrent();
            
            var userTask = Windows.System.User.FindAllAsync().AsTask();
            
            userTask.Wait();

            var users = userTask.Result;

            foreach (var user in  users)
            {
                var propTask = user.GetPropertiesAsync(new[] { "UserName" }).AsTask();
                
                propTask.Wait();
                
                var props = propTask.Result;

                foreach(var x in props)
                {
                    MessageBox.Show($"User is {x.Value}");
                }
            }            
        }

  
    }

}