Minimize application programmatically using C #

I have the following piece of code

List<String> sensitiveApps = testConnection.SelectSensitive();

foreach (string sensitiveApp in sensitiveApps)
        {
            Console.Write(sensitiveApp);

            // retrieve applications to minimize handle (connect to database and systematically minimize all applications?)
            IntPtr hwnd = UnsafeNativeMethods.FindWindow(sensitiveApp, null);
            StringBuilder stringBuilder = new StringBuilder(256);
            UnsafeNativeMethods.GetWindowText(hwnd, stringBuilder, stringBuilder.Capacity);
            Console.WriteLine(stringBuilder.ToString());

            if (!hwnd.Equals(IntPtr.Zero))
            {
                // SW_SHOWMAXIMIZED to maximize the window
                // SW_SHOWMINIMIZED to minimize the window
                // SW_SHOWNORMAL to make the window be normal size
                ShowWindowAsync(hwnd, SW_SHOWMINIMIZED);
            }
        }

      

        
        
        
      

    

Where sensitiveApps is a list containing the strings "Notepad", "Recuva" and "VLC media player 2.0.3".

However, the only application that can be minimized with this code is Notepad. Debugging the program finds that

Console.WriteLine(stringBuilder.ToString());

      

        
        
        
      

    

will return no value for the last two programs, but will return Untitled-Notepad.

Is there something I am doing wrong?