Missing DLL file. (PLEASE HELP)

Itsmeiko

so when ever i try and open the gamesalad installer it comes up with
"There is a problem with this Windows Installer package.
A DLL required for this install to complete could not be
run. Contact your support personnel or package vendor."
I'm sure this is an easy fix but I'm no computer wizz so I don't really understand whats wrong.

Thanks!