If full and absolute authorization cannot be granted, you may need to deactivate UAC which will allow full access.  But it can and will make your system's Program Files folder  vulnerable to malware and viruses.  The best recommendation is install Poser in it's own folder on the root drive away from Vista's/W7's Program Files folder.  Additionally, create external runtime folders to hold your content rather than loading into the main Poser folder.  You can separate your content by categories and organize it more cohesively.