title: Unable to install because a newer version of this product is already installed
body: <p>I have a setup project written in VS2010. The user launches the package, fills in all the forms, proceeds to the last "install" button, clicks on it and gets "Unable to install because a newer version of this product is already installed." . That's strange because the setup packages always warn about an already installed version before even showing any dialog forms. What are the possible causes of this error?
  Could this be because there was another product installed with the same upgrade code, but with different product code?
  The log goes below:</p>
  
  <pre><code>Action 10:03:20: AppSearch. Searching for installed applications
  Action start 10:03:20: AppSearch.
  Action ended 10:03:20: AppSearch. Return value 0.
  Action 10:03:20: FindRelatedProducts. Searching for related applications
  Action start 10:03:20: FindRelatedProducts.
  Action ended 10:03:20: FindRelatedProducts. Return value 0.
  Action 10:03:20: ERRCA_CANCELNEWERVERSION. 
  Action start 10:03:20: ERRCA_CANCELNEWERVERSION.
  DEBUG: Error 2835:  The control ErrorIcon was not found on dialog ErrorDialog
  The installer has encountered an unexpected error installing this package. This may indicate a problem with this package. The error code is 2835. The arguments are: ErrorIcon, ErrorDialog, 
  Unable to install because a newer version of this product is already installed.
  MSI (s) (E8:B4) [10:03:27:248]: Product: Contact Manager -- Unable to install because a newer version of this product is already installed.
  Action ended 10:03:27: ERRCA_CANCELNEWERVERSION. Return value 3.
  Action ended 10:03:27: INSTALL. Return value 3.
  </code></pre>