I guess I did not make it clear on the question at the first place. Because one can use previous versions of Winzip after the trial period with some naggings, I thought that was the case for WinZip v12, so I was surprised to find out that it prevented me from using it.
Now I am clear that WinZip stops working after the 45-day free trial period, according to http://www.winzip.com/clhm.htm
. I decide to use 7-zip instead.
Thanks for all the feedback. Appreciate that.