If you did install from the download page, then there might be something in your registry that is holding things up. Perhaps using something like Revo Uninstaller (paid) or Geek Uninstaller (free) might help resolve your issue. The Poser uninstaller leaves things behind in the registry and wiping those things out might get you past that. You'll need to re-register the program with your serial number in that case, because it will probably see it as a completely fresh install.