You have the wrong order of things and also forgot the variable name in the last statement.
Process myProcess = new Process();
myProcess.StartInfo.UseShellExecute = false;
myProcess.Start();
StartInfo.FileName = @"C:\Users\MyName\Desktop\NewFolder\Application.exe";
should be
Process myProcess = new Process();
myProcess.StartInfo.UseShellExecute = false;
myProcess.StartInfo.FileName = @"C:\Users\MyName\Desktop\NewFolder\Application.exe";
myProcess.Start();