Hi Rogerio.

GetProcessByName is a lot simpler, but has some disavantages:

• it will allow 2 instances to run if you change the .EXE name
• if you have 2 separate applications with the same name, it won't allow them to run at the same time
• Mutex can work with a Global escope, so it will make sure the application run only once in the entire system, even on Terminal Services
• apparently, GetProcessByName may not access minimized windows properly
  

Hi Ivan...

        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            //-- Evita mais de uma instância
            bool ok;
            Mutex loMutex = new Mutex(true, Application.ProductName + Application.ProductVersion, out ok);
            if (!ok)
            {
                MessageBox.Show("Aplicativo já está em execução");
                Application.Exit();
                return;
            }

            //-- Enable visual styles on the application
            Application.EnableVisualStyles();

            ...

            //-- Run the application
            StrataFrameApplication.RunApplication();

            //-- Stop the session monitoring before the application exits to remove the low-level event handlers
            SessionLock.StopSessionMonitoring();

            GC.KeepAlive(loMutex);


        }



Rogério Mauri

---

Yep, that is it.

I go a bit further on my applications since I have a Licensing control based on licenses per machine. So I create the Mutex under a Global state, this way I can count the number of instances running even on various Terminal Service sessions.