Google didn't help...All results are unuseful...

Create a new registry key: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run and then add a new key-value (MyApp - C:\MyApp.exe)

using Microsoft.Win32;

private void CreateStartup() {

RegistryKey Key=Registry.LocalMachine.CreateSubKey("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run");
Key.SetValue("MyApp", Application.ExecutablePath);
}