I don't understand what you mean by "win zip" the file, do you work on a Mac ?
I said "unzip" the file, you have to have a compression software
which can handle the .rar files ,
I just installed Astrotite for that , is free , you can download it here
or you can make the choice of another program
from the compression rubric, just check that can handle the .rar files.
Hope that can help