Once you complete with Demo version testing you will definitely want to remove a Gres CMS Demo footer link and all the limitations a Demo version has. To remove all the limitations you’re to obtain a unique license serial number (license). All you need is to apply license serial number via administrative panel at Tools > Tools > License. CMS reinstallation not required.
In order to run Gres CMS and use it to its full capability, you should first confirm your server meets the following requirements:
Apache, Nginx or IIS webserver
PHP 5.3.3. or higher, with support for:
PHP Memory Limit at least 64 MB (more might be required for the processing and handling of large image files.)
MySQL 5.1.5 or Higher
If you’re unsure if your webhost supports all this, don’t worry, even shared webhosting packages usually meet these requirements.