title: Update an existing installation using InstallShield LE
body: <p>We've got a a quite simple WinForms application. I've created an installation using InstallShield LE which works fine on the first install. I'd like that users will be able to run  the installation also for updating an existing copy. The problem is that I can't figure out what is the right way to create this update package. I've tried:</p>
  
  <p>Changing the Product Code - the installation works but a new entry is being created in Add/Remove programs and the old entry is not removed.</p>
  
  <p>Keeping the Product Code - Windows installer shouts: "another version of this product is already installed"</p>
  
  <p>Tried to play with other codes (Upgrade Code / Product Version) - doesn't help</p>
  
  <p>Is there any easy way to create this? Maybe something to tell the installer to remove its previous version if exist?</p>