title: How can I know if R is running on 64 bits versus 32?
body: <p>My version output is:</p>
  
  <pre><code>&gt; version
                 _                            
  platform       x86_64-w64-mingw32           
  arch           x86_64                       
  os             mingw32                      
  system         x86_64, mingw32              
  status                                      
  major          2                            
  minor          15.2                         
  year           2012                         
  month          10                           
  day            26                           
  svn rev        61015                        
  language       R                            
  version.string R version 2.15.2 (2012-10-26)
  nickname       Trick or Treat    
  </code></pre>
  
  <p>where os is mingw32. Does that mean I'm using only 32 bits? How can I change that?</p>