For opening or extracting zip files you don’t actually need any program. There are several ways to do it so I will show you a bunch of them so you can use the one you prefer.

Opening zip files with 7ZIP

This is a free program called 7zip:

http://www.7-zip.org/

 

And here you have some tutorials on youtube:

https://www.youtube.com/results?search_query=how+to+open+a+zip+file+with+7zip

 

Opening zip files in Windows 8

Opening zip files in Windows 7

Opening zip files in Mac

 

I hope this helps! Thank you!