What version of Premiere Elements are you using and on what computer operating system is it running? Just background for any subsequent questions that need specifics.
Is the SmartSound.zip in the following Adobe document the one you are trying to use?
If so, that is the one and only download that I have ever come across and no problems have been reported to date concerning the integrity of that download. SmartSound has been discontinued in Premiere Elements 12 which now has a feature called Music Score which is similar in principle to SmartSound but not SmartSound.
Have you disabled the antivirus and firewall or written permissions to complete the task?
Please supply more information.