When I created my first content area (in a local site) per the PCMS Builder Getting Started guide, the PCMS Builder installation automatically created the folders I listed above in the site root. There was no prompt for a folder in which to place the folders and files it created.
I uploaded the folders and files the install created to the same location -- folders listed above are in the site root.
I gave Write permissions to Everyone on the site root folder, and still got the file permissions error when trying to run on the production site. I propagated Write permissions to every folder in the entire domain, and I still get the file permissions error. My host server (IIS) is running PHP Version 5.2.13 and MySQL 5.