PROBLEMS IN OPENING LIBREOFFICE 4.4.1 MSI FILE IN WIN 7

I have downloaded LibreOffice 4.4.1 windows version but am unable to open it in Windows 7. Trying to install the file gives the error message "“This installation package could not be opened. Contact the application vendor to verify that this is a valid Windows Installer package”.
The file has been downloaded from the official site and is complete. Have already downloaded the file three times afresh but with the same results. I would like to state that my laptop already has prior version of LibreOffice installed. Any clues as to how this problem could be resolved ? Could the earlier version be causing a conflict ? Would deeply appreciate any assistance rendered.

I had similar problem. In my case the installation files had the wrong extension .man I think. Changing to .msi resolved the issue.