I use Winzip, and have it set for "Use Full Path Information."

You can use the built in uncompress in Windows if you like. Just tell it to "Extract Here." You then can find the "Runtime" folder that results... may be the top folder, may be the next one down depending on how the Zip was created... and move it to the runtime folder where you have all your content. If you are using the default Poser setup this is located at: "C:/Users/Public/Documents/Poser Pro 2014 Content/Runtime. (You don't say what version of Poser you are running... it could be different from what I say here.) Drop the folder in the PP Content folder. Tell it to Merge the contents. Your new content is installed.

Someone else may know an even easier way... I use Winzip.

(I just cross-posted with Hborre... he is basically telling you the same thing I am. Hope that between us, it makes sense to you.)