MSDN Library

using System;
using System.Security.Cryptography.X509Certificates;

public class Example
{
    public static void Main()
    {
        try
        {
            // Get the current user's personal certificate store
            X509Store store = new X509Store(StoreName.My, StoreLocation.CurrentUser);
            store.Open(OpenFlags.ReadOnly);

            // Check if there are any certificates in the store
            if (store.Certificates.Count > 0)
            {
                // Get the first certificate
                X509Certificate2 certificate = store.Certificates[0];

                // Get the thumbprint
                string thumbprint = certificate.Thumbprint;

                Console.WriteLine($"Certificate Thumbprint: {thumbprint}");
            }
            else
            {
                Console.WriteLine("No certificates found in the CurrentUser Personal store.");
            }

            store.Close();
        }
        catch (Exception ex)
        {
            Console.WriteLine($"An error occurred: {ex.Message}");
        }
    }
}