Reading DigitalProductId from registry comes back null

Question

I'm Currently trying to get my Product key of my windows 7 installation from the registry. but for some reason DigitalProductId is coming back null. And I can't figure out why it's doing that.

I can read other values in the "NT\Current Version" just fine. like "productName" but when it comes to the digitalProductId I'm getting nothing.

here is my code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Microsoft.Win32;
using System.Collections;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            byte[] results = Form1.GetRegistryDigitalProductId(Form1.Key.Windows);
            string cdKey = Form1.DecodeProductKey(results);
            MessageBox.Show(cdKey, "HWID()", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }


        public enum Key { Windows };
        public static byte[] GetRegistryDigitalProductId(Key key)
        {
            byte[] digitalProductId = null;
            RegistryKey registry = null;
            switch (key)
            {
                case Key.Windows:
                    registry =
                      Registry.LocalMachine.
                        OpenSubKey(
                          @"SOFTWARE\Microsoft\Windows NT\CurrentVersion",
                            false);
                    break;
            }
            if (registry != null)
            {
                digitalProductId = registry.GetValue("DigitalProductId")
                  as byte[];
                registry.Close();
            }
            return digitalProductId;
        }
        public static string DecodeProductKey(byte[] digitalProductId)
        {
            const int keyStartIndex = 52;
            const int keyEndIndex = keyStartIndex + 15;
            char[] digits = new char[]
     {
       'B', 'C', 'D', 'F', 'G', 'H', 'J', 'K', 'M', 'P', 'Q', 'R', 
       'T', 'V', 'W', 'X', 'Y', '2', '3', '4', '6', '7', '8', '9',
     };
            const int decodeLength = 29;
            const int decodeStringLength = 15;
            char[] decodedChars = new char[decodeLength];
            ArrayList hexPid = new ArrayList();
            for (int i = keyStartIndex; i <= keyEndIndex; i++)
            {
                hexPid.Add(digitalProductId[i]);
            }
            for (int i = decodeLength - 1; i >= 0; i--)
            {
                if ((i + 1) % 6 == 0)
                {
                    decodedChars[i] = '-';
                }
                else
                {
                    int digitMapIndex = 0;
                    for (int j = decodeStringLength - 1; j >= 0; j--)
                    {
                        int byteValue = (digitMapIndex << 8) | (byte)hexPid[j];
                        hexPid[j] = (byte)(byteValue / 24);
                        digitMapIndex = byteValue % 24;
                        decodedChars[i] = digits[digitMapIndex];
                    }
                }
            }
            return new string(decodedChars);
        }

    }
}

I'm new to c# and I'm trying to follow this guide. http://www.ultimateprogrammingtutorials.info/2013/05/how-to-get-windows-product-key-in-c.html

But I'm having trouble getting to work correctly.

Thanks

Answer 1

You can use your code as-is if you target 64-bit in your build.

---

Otherwise, you get directed here, and you might not find the key you're looking for:

SOFTWARE\Wow6432Node\...

So use this code if you have to target 32-bit:

var baseKey = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry64);

var reg = baseKey.OpenSubKey(@"SOFTWARE\Microsoft\Windows NT\CurrentVersion", false);

var digitalProductId = reg.GetValue("DigitalProductId") as byte[];

Answer 2

public static string getKey(string from = @"SOFTWARE\Microsoft\Windows NT\CurrentVersion", string valueName = "DigitalProductId")
{
            RegistryKey hive = null;
            RegistryKey key = null;
            try
            {
                var result = string.Empty;
                hive = RegistryKey.OpenRemoteBaseKey(RegistryHive.LocalMachine, Environment.MachineName);
                key = hive.OpenSubKey(from, false);
                var k = RegistryValueKind.Unknown;
                try { k = key.GetValueKind(valueName); }
                catch (Exception) { }

                if (k == RegistryValueKind.Unknown)
                {
                    key.Close();
                    hive.Close();
                    hive = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry64);
                    key = hive.OpenSubKey(from, false);
                    try { k = key.GetValueKind(valueName); }
                    catch (Exception) { }
                }

                if (k == RegistryValueKind.Binary)
                {
                    var pivot = 0;
                    var bytes = (byte[])key.GetValue(valueName);
                    var ints = new int[16];
                    for (var i = 52; i < 67; ++i) ints[i - 52] = bytes[i];
                    for (var i = 0; i < 25; ++i)
                    {
                        pivot = 0;
                        for (var j = 14; j >= 0; --j)
                        {
                            pivot <<= 8;
                            pivot ^= ints[j];
                            ints[j] = ((int)Math.Truncate(pivot / 24.0));
                            pivot %= 24;
                        }
                        result = possible_chars[pivot] + result;
                        if ((i % 5 == 4) && (i != 24))
                        {
                            result = "-" + result;
                        }
                    }
                }
                return result;
            }
            catch (Exception) { return null; }
            finally
            {
                 key?.Close();
                 hive?.Close();
            }
}
private static readonly string possible_chars = "BCDFGHJKMPQRTVWXY2346789";