It boils down to you having to download a superior zipper once from http://www.7-zip.org
and enjoy the increased speed you now get the often huge downloads from the vault for life 🙂
MAC users should download http://www.zipeg.com if they have difficulties "unzipping" .7z
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.7z has turned out to be SO popular that winZIP (at least from Version 12) found themselves "forced" to also be able to un7zip = I have V12 and it works fine
...BUT I don't use winZIP because I find FREE .7z MUCH better 🙂