You can create a process and set the ProcessWindowStyle property to Hidden:
string path = Program.DriveName + "\\" + txtName.Text + ".bat";
StreamWriter sw = new StreamWriter(path);
sw.WriteLine("START /d " + "\"" + "C:\\Program Files\\TestSetup" + "\"" + " StkView.exe % " + result);
sw.Close();
Process proc = new Process();
proc.StartInfo.FileName = path;
proc.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
proc.Start();
Also you can execute the command without writing it into a bat file by passing it as an argument to the cmd file:
Process proc = new Process();
proc.StartInfo.FileName = "cmd";
proc.StartInfo.Arguments = "/cSTART /d " + "\"" + "C:\\Program Files\\TestSetup" + "\"" + " StkView.exe % " + result;
proc.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
proc.Start();