I think you might have dropped it in the wrong runtime. There will be two runtimes in Poser 10 folders on your system. One will be in program files. Don't put anything in this. Another should be in public documents if you followed the default install of Poser. If you put it in this it will show up, BUT it is not a good idea. You will find in this poser 10 folder another folder called downloads which contains a yet another folder named runtime. You can put it in there.

But you might want to create a new library. I've explained about this here

https://www.renderosity.com/mod/forumpro/?thread_id=2924209