unable to update to 2.5

  I'm new to using cce.  I downloaded version 2.4225190.192 to my download folder unzipped it and left it there.  Opening it, it says that a download is available using IE.  I OK it and IE asks if I want to, run, save, or save as.  I've tried doing it all three ways, and an unzipped file gets saved to my download folder.  When I unzip it and try to run it I get the message that CCE has stopped working.  I was able to scan my computer by cancelling and not using the update.  
  My computer is running Vista 32 with all the ms updates.  The only thing unusual is that I have Java turned off.  Any help would be greatly appreciated, thanks in advance for any guidance.