title: Updating Xcode from 4.1 to 4.2: No "Install Xcode.app" in Applications folder
body: <p>I've updated Xcode from 4.1 to 4.2 in Mac App Store but Xcode is still 4.1.</p>
  
  <p>In Mac App Store now, no update available anymore. Xcode in Mac App Store does not appear like installed application because the button is labeled as "FREE" then "INSTALL APP" not "INSTALLED" as expected. When I clicked "FREE" and then "INSTALL APP", it alerts</p>
  
  <p>"<strong>We could not complete you purchase</strong>  <br />
  Xcode is already installed on this computer. Choose Software Update from the Apple menu to check for available updates."</p>
  
  <p>I followed the instruction but there is no available update for Xcode. I also tried to restart my computer for a few times but no effect.</p>
  
  <p>Edited: There is no <strong>Install Xcode</strong> in my Applications folder as well.</p>
  
  <p>Is there any suggestion? Thank you.</p>