No, if the Poser program is installed without content; yes, if content is loaded into the same parent runtime. Window UAC prevents write backs to files in that location, and shutting down UAC will leave your system vulnerable to malware attacks. In addition, you will have problems accessing content files, and saving character, props, poses and textures. And if anything manages to get saved back to the Poser Library, you will not find it in the Poser runtimes but rather in a virtual location, For that reason, the most current versions of Poser will install content in a shared folder location away from Program Files.