HWID für Elitepvpers in C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.Runtime.InteropServices;
using System.Net;
using System.IO;
namespace HWID
{
    public class HWID
    {
        [Flags]
        private enum DockInfo
        {
            DOCKINFO_DOCKED = 0x02,
            DOCKINFO_UNDOCKED = 0x01,
            DOCKINFO_USER_SUPPLIED = 0x04,
            DOCKINFO_USER_DOCKED = 0x05,
            DOCKINFO_USER_UNDOCKED = 0x06
        }

        [StructLayout(LayoutKind.Sequential)]
        private class HW_PROFILE_INFO
        {
            [MarshalAs(UnmanagedType.U4)]
            public Int32 dwDockInfo;

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 39)]
            public string szHwProfileGuid;

            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 80)]
            public string szHwProfileName;
        }
        [DllImport("advapi32.dll", SetLastError = true)]
        private static extern bool GetCurrentHwProfile(IntPtr lpHwProfileInfo);
        [DllImport("kernel32.dll")]
        private static extern long GetVolumeInformation(string PathName, StringBuilder VolumeNameBuffer, UInt32 VolumeNameSize, ref UInt32 VolumeSerialNumber, ref UInt32 MaximumComponentLength, ref UInt32 FileSystemFlags, StringBuilder FileSystemNameBuffer, UInt32 FileSystemNameSize);

        public HWID()
        {
        }
        

        public string strHWID()
        {
            HW_PROFILE_INFO info = ProfileInfo();
            string GUID = info.szHwProfileGuid.ToString();
            string volumeserial = GetVolumeSerial("C");
            return md5(GUID + volumeserial);         
        }

        public static string[] GetHWID(string HWID)
        {
            WebRequest Request = WebRequest.Create("http://elitepvpers.com/api/hwid.php?hash=" + HWID);
            Stream requeststream = Request.GetResponse().GetResponseStream();
            StreamReader read = new StreamReader(requeststream);
            string src = read.ReadToEnd();
            string[] userid = StringBetween("<userid>", "</userid>", src, false, false);
            string[] username = StringBetween("<username>", "</username>", src, false, false);
            string[] joindate = StringBetween("<joindate>", "</joindate>", src, false, false);
            string[] posts = StringBetween("<posts>", "</posts>", src, false, false);
            string[] thanks = StringBetween("<thanks>", "</thanks>", src, false, false);
            string[] usergroup = StringBetween("<usergroup>", "</usergroup>", src, false, false);
            string[] result = { userid[0], username[0], joindate[0], posts[0], thanks[0], usergroup[0] };
            return result;
        }

        //md5 func//
        private string md5(string input)
        {
            MD5 md5 = System.Security.Cryptography.MD5.Create();
            byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(input);
            byte[] hash = md5.ComputeHash(inputBytes);
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < hash.Length; i++)
            {
                sb.Append(hash[i].ToString("X2"));
            }
            return sb.ToString();
        }

        //String between func//
        private static string[] StringBetween(string strBegin, string strEnd, string strSource, bool includeBegin, bool includeEnd)
        {

            string[] result = { "", "" };
            int iIndexOfBegin = strSource.IndexOf(strBegin);
            if (iIndexOfBegin != -1)
            {
                if (includeBegin)
                    iIndexOfBegin -= strBegin.Length;
                strSource = strSource.Substring(iIndexOfBegin + strBegin.Length);
                int iEnd = strSource.IndexOf(strEnd);
                if (iEnd != -1)
                {
                    if (includeEnd)
                        iEnd += strEnd.Length;
                    result[0] = strSource.Substring(0, iEnd);
                    if (iEnd + strEnd.Length < strSource.Length) result[1] = strSource.Substring(iEnd + strEnd.Length);
                }
            }
            else
                result[1] = strSource;
            return result;
        }


        //Information things//
        private HW_PROFILE_INFO ProfileInfo()
        {
            HW_PROFILE_INFO profile;
            IntPtr profilePtr = IntPtr.Zero;
            try
            {
                profile = new HW_PROFILE_INFO();
                profilePtr = Marshal.AllocHGlobal(Marshal.SizeOf(profile));
                Marshal.StructureToPtr(profile, profilePtr, false);

                if (!GetCurrentHwProfile(profilePtr))
                {
                    throw new Exception("Error cant get current hw profile!");
                }
                else
                {
                    Marshal.PtrToStructure(profilePtr, profile);
                    return profile;
                }
            }
            catch (Exception e)
            {
                throw new Exception(e.ToString());
            }
            finally
            {
                if (profilePtr != IntPtr.Zero) Marshal.FreeHGlobal(profilePtr);
            }
        }

        private string GetVolumeSerial(string strDriveLetter)
        {
            uint serNum = 0;
            uint maxCompLen = 0;
            StringBuilder VolLabel = new StringBuilder(256);
            UInt32 VolFlags = new UInt32();
            StringBuilder FSName = new StringBuilder(256);
            strDriveLetter += ":\\";
            long Ret = GetVolumeInformation(strDriveLetter, VolLabel, (UInt32)VolLabel.Capacity, ref serNum, ref maxCompLen, ref VolFlags, FSName, (UInt32)FSName.Capacity);
            return Convert.ToString(serNum);
        }
    }
}