title: trouble with ProcessBuilder
body: <pre><code>// following code works fine n open notepad...   
  class demo
  {
  public static void main(String args[])
  {
      try{
      ProcessBuilder pb=new ProcessBuilder("notepad");
      pb.start();
      }catch(Exception e)
      {System.out.print(e);}
  }
  }
   //however the above code throws an exception when any other system program is executed
  class demo
  {
  public static void main(String args[])
  {
      try{
      ProcessBuilder pb=new ProcessBuilder("calculator");
      pb.start();
      }catch(Exception e)
      {System.out.print(e);}
  }
  }
  </code></pre>
  
  <p>the above program throws following exception:</p>
  
  <pre><code>java.io.IOException: Cannot run program "Calculator": CreateProcess error=2, The system cannot find the file specified
  </code></pre>