I'd have to know how you are doing it to tell you what you are doing wrong, I mean youa ren't just unzipping the items to your My libarary folder are you? Or depending on DIM or CMS; which only work with DAZ content.

Seriously there is nothing to it but unzip, check the folder, cut and paste, done.

What you get here wont be in the cluster F file struckture of the Studio content folder, it will be in a runtime for Poser; unless other wise specified.

But with out more details I can't help.

As in what are you trying to install, where are you installing it to, which application is it for, how are you trying to install it.

Installing content is actually quite easy as long as you don't try to do it the easy. or automatic way.