All the permission already set to 777 for installation, but still its not going through.
Though I am already on 5th step why it says, this error doesn’t make any sense.
Forbidden
You don’t have permission to access /oxid/setup/index.php on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
Can you check the server (apache) error-logfiles? Is it a Debian? You will find the logs then here /var/log/apache (or maybe apache2).
Must be defenitely a misconfiguration of apache-server, perhaps you need to configure “AllowOverride” to “All” in the main apache configuration. And if there is running Confixx or SysCP or any similar webadmin-interface, you need to check the configuration for them as well. They sometimes block other configs.