NHK When you say unzip the zip file, which file are you talking about? The additional content files are extra zips that you have to download separately, there are a number of them, I can't remember how many. To download them you have to enter your poser serial number so you can't get them if you are using the 21 day free trail of poser.

Once you have downloaded them see this thread about installing them. No content should go into the poser folder in programs.