4.2.7 windows ver installer from libreoffice.org shows -
“This installation package could not be opened. Contact the application vendor to varify that this is a valid Windows Installer package.” - error message when trying to install on Windows 7 Home Premium
Using a VAIO with Office 2010 and Avast Premier installed…
Please help
Your download target is OK. However you cannot exclude a download problem, which means that something got corrupt.
You can check if the download is correct by using the hash tag / check sum. You find the hash tag information from here:
http://downloadarchive.documentfoundation.org/libreoffice/old/ > select the exact version you have (4.2.7.1 or 4.2.7.2) > click your version > select "win" and click > click x86 > slect the file you downloaded (it should be the one on top) and click "Details" > there you find Hash tags > choose the one your hash tag you matching your checksum verifier.
If you don’t have a check sum verifier look in the internet and you will find some. Here is what I am using as an example.
If the check number is correct and the installation is not running, then please provide exact information on what you did. Steps and results.
Thank you for your reply ROSt52!!
It was a download problem indeed!!! I downloaded the installer straight from the archive you pointed me to and Lo and Behold! Works like a charm 
Thanks again for the help
Cheers