Which poser root directory did you unzip to? When you install poser two runtimes are created, if following the defaults one will be in you programs folder and the other in your public documents folder. All content should be added to the folder in the public documents. BUT Rather than load new content into the poser you are better off creating new runtimes, in future if you want to upgrade poser you don't want to have the default content duplicated. Create a folder ANYNAME and in this create a folder "runtime" Make sure it is a public folder that poser can write to. Now use the add library function (top right corner of the library pane), this opens an explorer window, navigate to the runtime folder you have created and click ok, a library ANYNAME should now be added. If you get an error message it is probably because poser can't write to this folder so check the folder properties to allow poser to write to it. You should now be able to load content to this folder, either by using the install from zip in poser's file menu is the content is properly packaged or by manually unzipping.