A Zip utility like the 2 you have referred to is used to compress files! It is possible to "zip" several files into a smaller package, thereby making it easier to download!
Whenever you come in contact with a file that ends in ".zip" then you will need a Zip utility to "unpack" the files contained within. Untill, and unless, you "unpack" these files, you will not be able to utilise that ".zip" program, for example, your wintop.zip
After you have installed Winzip, then go back to the wintop.zip file, and right-click it. You should get options, one of which will be unzip.
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