Having a Problem Installing CiviCRM 4.7.25 on WordPress
The CiviCRM "plugin" for Wordpress CMS is not installed like a conventional Wordpress plugin.  There are many more things to be considered and you would be advised to read and follow all the stages described in the following Wordpress Installatin Guide for CiviCRM at https://docs.civicrm.org/sysadmin/en/master/install/wordpress/

Hope this helps.