Thread t;
        private const string initialDir = "C:\\";
        private const string FileName = "aa.jpg";
        private void button1_Click(object sender, EventArgs e)
        {
            string combinedDir = initialDir + FileName;
            if (File.Exists(combinedDir))
            {
                openFileDialog1.InitialDirectory = initialDir;
                openFileDialog1.FileName = FileName;
                BeginInvoke((Action)(() => openFileDialog1.ShowDialog()));
                t = new Thread(new ThreadStart(SendKey));
                t.Start(); // Thread starts.
            }
            else
            {
                openFileDialog1.InitialDirectory = initialDir;
                openFileDialog1.FileName = FileName;
                openFileDialog1.ShowDialog();
            }
        }

        private void SendKey()
        {
            Thread.Sleep(100);
            SendKeys.SendWait("+{TAB}");
            SendKeys.SendWait("+{TAB}");
            SendKeys.SendWait(FileName);
        }