If you have installed Poser to the default locations, the folder you are looking for will be in Program files (x86)/Smith Micro/Poser 10 As far as Renderosity content is concerned, just download the zip files. Then in Poser 10 you can go to the content room (the last tab along the top of the document window, the one after setup. You can then just click on the install from zip archive button. Poser will give you a choice of all the runtimes you have in your library, choose the one you want to put the content in and poser does the rest. (I've only ever had one item from here that this didn't work for, and that was a very old one.)