Program.cs

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace RGBSync
{
    static class Program
    {

        private static Mutex mutex = null;

        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            const string appName = "RGBSyncV2";
            bool createdNew;
            mutex = new Mutex(true, appName, out createdNew);

            if (!createdNew)
            {
                //app is already running! Exiting the application  
                return;
            }
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Settings());
        }
    }

    
}