EXE file is existing in c#

If you only need to detect a previous instance, then a Mutex is easy and effective. Note that you should place this code in the Program.cs file, not in the Form class. Put this code just before the line that says "Application.Run(new Form1());" or something such as that. Note that the MutexName must be unique within the system.

bool WasCreated;
const string MutexName = "WhateverNameYouWant";
Mutex m = new Mutex(true, MutexName, out WasCreated);
if (!WasCreated)
{
// MessageBox.Show("A previous instance exists");
return;
}

Also, after the "Application.Run(new Form1());" you need to also do the following:

GC.KeepAlive(m);

That line is not important for small programs, but always use it anyway when using the above code that uses the Mutex.

You can get the list of running processes from your system and check your application is present or not. If it present then alert the customer the  application is already running.


  System.Diagnostics.Process[] process= System.Diagnostics.Process.GetProcessesByName("exeName");
  if (process.Length > 0)
  MessageBox.Show("Application is already running");