ZIP Help

I have a mac, and i am trying to open some software but it is zipped and gives me an error message like this “unable to unarchive “” ERROR 78-FUNCTION NOT IMPLEMENTED.” Is there a program that i will need to unzip this possibly winzip?

Thanks for everyones help!!

There is a free version of winzip. Depending on the file extension there are various different zip progs. For mac you can use Zipit.