You cannot block these results at present. Many of thes files have the same size and a size filter is something we have been asking for for ages. (with no luck).
Other types of filter are impracticle or impossible due to the fact that viruses can auto reproduce search terms for genuine searches.
Programmes (.exe) and Zip files should be avoided unless you are very sure what you are doing and have fully up to date virus protection (Not downloaded off Limewire
) wma and wmv files are also risky fellows.