If the zips are less than 1 MB (1,000 KB) then they're most likely viruses anyway so just as well you can't open them. Unless your winzip is already affected. I had an issue 4-5 yrs ago where my stuffit expander became effected with a virus & affected everything that passed thru it! So be sure .. check your system over. I'd advise checking with Norbie here
NorbiesWorld (click on link)