Please note that the Ultimate SEO URLs' support-thread is located here: https://www.zen-cart.com/showthread....Support-Thread

Windows IIS doesn't use the .htaccess file that's distributed as part of the USU zip-file. You'll need to convert the Apache .htaccess directives to their IIS web.config file counterparts to enable USU to operate in that Windows IIS environment; see this link for sample instructions.