Still can't launch an external executable through NativeProcess

I have been waiting for so long for this feature - and still didn't manage to use it. I have this simple task to do: Open notepad (under windows) through Adobe AIR. Here's my code

   function init(){
     var process;
     var nativeProcessStartupInfo = new air.NativeProcessStartupInfo();
     var file = new air.File("C:\windows\System32\notepad.exe");

              nativeProcessStartupInfo.executable = file;
    
     process = new air.NativeProcess();
              process.start(nativeProcessStartupInfo);

    }

When I execute this (onload) I get this error:

NativeProcessStartupInfo.executable does not specify a valid executable file

any help?

thanks,

George