Sorry for the delay in answering, I have not been getting notifications from the forum.
Regretfully building an installer that works with every system is not as easy as it should be. Things change in operating systems, people use a variety of 'virus protection' packages, and generally behavior in systems is not all the same. If it were, it'd be easy. the Readme file included with the package should have helped to solve these problems by telling you to shut of virus protection, etc. It also should have mentioned doing a search for files to determine if the installation was indeed a success. there is a fairly extensive troubleshooting page on my website:
Troubleshooting for Elements 4
This includes serarate mac and PC installation instructions.
I'd be glad to hear more about what is going on...I may be catching up with Elements 5 and 6 soon, and I am hoping to make user experience better.