ya, this is on w2k3/iis6/php5/mysql5. Permissions I'm setting explicit to the IUSR account per your document. For example includes directoy is set to full permissions but each file in includes directory is set to read and write only, per the install document. I continue to get the Failed to write config error.
Do you have an IIS setup you can grab a screenshot of the includes permissions and send out?
