title: How to make an application not portable?
body: <p>I am trying to make an application that should not portable between computers or<br/> between users of the same computer.<br/>
  Which is the best way to do this?<br/></p>
  
  <p><b>edit:</b>
  By <code>not portable</code> I meant, the application should not be usable without installing it. ie) moving the installed folder to a different computer or different user login of the same computer.</p>
  
  <p>How can we get an id that is always unique to a user login in a computer?.</p>
  
  <p>please excuse my poor english.</p>