The Poser installer does not remove files you've added to the Poser program folder or any content beyond the basic content that is installed with Poser. But, a re-installation will over write the python buttons scripts with the original ones. If you manually add some buttons to the python buttons by editing that file, write protect the file. The next time you update Poser it will ask if you want to skip the file. And, you do. There are a couple of bits of standard content that I keep modified this way as well.