VulnService.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Threading.Tasks;

namespace WindowsService1
{
    public partial class VulnService : ServiceBase
    {
        public VulnService()
        {
            InitializeComponent();
        }

        protected override void OnStart(string[] args)
        {
            LogService("Service is Started");
        }

        protected override void OnStop()
        {
            LogService("Service Stoped");
        }

        private void LogService(string content)
        {
            FileStream fs = new FileStream(@"c:\VulnServiceLog.txt", FileMode.OpenOrCreate, FileAccess.Write);
            StreamWriter sw = new StreamWriter(fs);
            sw.BaseStream.Seek(0, SeekOrigin.End);
            sw.WriteLine(content);
            sw.Flush();
            sw.Close();
        }
    }
}