It says that the possible solution is "Run the install again" but I have reinstalled it for many times. It still can't work and still stop at 42%.
You can try an alternative resource for the download. You haven't specified the version you are trying to download though so you will have to search the site for it...
You can download the trial version of the software thru the page linked below and then use your current serial number to activate it.
Be sure to follow the steps outlined in the Note: Very Important Instructions section on the download pages at this site and have cookies enabled in your browser or else the download will not work properly.
http://prodesigntools.com/tag/ddl