Mutex - Singleton Help

am using the following piece of code to ensure that my application only runs once, however I have a few questions about it.

      static Mutex m_Mutex; << in c# I assume that when the methods are static, so are the private members.

      public static void Run(Form mainForm)
      {
         if(IsFirstInstance())
         {
            Application.ApplicationExit += new EventHandler(OnExit);
            Application.Run(mainForm);
         }
      }
     
The following is causing me some confusion, when the application starts it creates a newly named Mutex. It then calls WaitOne and determines whether it receives any messages, if it does it returns true otherwise false. My questions are this, when the next application comes to create a new mutex with the same name, what exactly happens? Does it deny it therefore this is why the WaitOne does not receive any messages, also the timespan is set to zero, how can the mutex determine if any messages have been recieved in zero time?

      static bool IsFirstInstance()
      {
         m_Mutex = new Mutex(false,"SingletonApp Mutext");
         bool owned = false;
         owned = m_Mutex.WaitOne(TimeSpan.Zero,false);
         return owned ;
      }