Program.cs

using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;

namespace VSKeyExtractor
{
    struct Product
    {
        public string Name { get; }
        public string GUID { get; }
        public string MPC { get; }
        public Product(string Name, string GUID, string MPC)
        {
            this.Name = Name;
            this.GUID = GUID;
            this.MPC = MPC;
        }
    }

    class Program
    {
        static readonly List<Product> Products = new List<Product>
        {
            new Product("Visual Studio Express 2012 for Windows Phone"  , "77550D6B-6352-4E77-9DA3-537419DF564B", "04937"),
            new Product("Visual Studio Professional 2012"               , "77550D6B-6352-4E77-9DA3-537419DF564B", "04938"),
            new Product("Visual Studio Ultimate 2012"                   , "77550D6B-6352-4E77-9DA3-537419DF564B", "04940"),
            new Product("Visual Studio Premium 2012"                    , "77550D6B-6352-4E77-9DA3-537419DF564B", "04941"),
            new Product("Visual Studio Test Professional 2012"          , "77550D6B-6352-4E77-9DA3-537419DF564B", "04942"),
            new Product("Visual Studio Express 2012 for Windows Desktop", "77550D6B-6352-4E77-9DA3-537419DF564B", "05695"),

            new Product("Visual Studio 2013 Professional"               , "E79B3F9C-6543-4897-BBA5-5BFB0A02BB5C", "06177"),
            new Product("Visual Studio 2013 Ultimate"		            , "E79B3F9C-6543-4897-BBA5-5BFB0A02BB5C", "06181"),
            
            new Product("Visual Studio 2015 Enterprise"                 , "4D8CFBCB-2F6A-4AD2-BABF-10E28F6F2C8F", "07060"),
            new Product("Visual Studio 2015 Professional"               , "4D8CFBCB-2F6A-4AD2-BABF-10E28F6F2C8F", "07062"),

            new Product("Visual Studio 2017 Enterprise"                 , "5C505A59-E312-4B89-9508-E162F8150517", "08860"),
            new Product("Visual Studio 2017 Professional"               , "5C505A59-E312-4B89-9508-E162F8150517", "08862"),
            new Product("Visual Studio 2017 Test Professional"          , "5C505A59-E312-4B89-9508-E162F8150517", "08866"),

            new Product("Visual Studio 2019 Enterprise"                 , "41717607-F34E-432C-A138-A3CFD7E25CDA", "09260"),
            new Product("Visual Studio 2019 Professional"               , "41717607-F34E-432C-A138-A3CFD7E25CDA", "09262"),

            new Product("Visual Studio 2022 Enterprise"                 , "1299B4B9-DFCC-476D-98F0-F65A2B46C96D", "09660"),
            new Product("Visual Studio 2022 Professional"               , "1299B4B9-DFCC-476D-98F0-F65A2B46C96D", "09662"),
        };

        static void Main()
        {
            foreach (var product in Products) ExtractLicense(product);
        }

        private static void ExtractLicense(Product product)
        {
            var encrypted = Registry.GetValue($"HKEY_CLASSES_ROOT\\Licenses\\{product.GUID}\\{product.MPC}", "", null);
            if (encrypted == null) return;
            try
            {
                var secret = ProtectedData.Unprotect((byte[])encrypted, null, DataProtectionScope.CurrentUser);
                var unicode = new UnicodeEncoding();
                var str = unicode.GetString(secret);
                foreach (var sub in str.Split('\0'))
                {
                    var match = Regex.Match(sub, @"\w{5}-\w{5}-\w{5}-\w{5}-\w{5}");
                    if (match.Success)
                    {
                        Console.WriteLine($"Found key for {product.Name}: {match.Captures[0]}");
                    }
                }
            }
            catch (Exception) { }
        }
    }
}