hide_admin_menu.php

<?php
function remove_menus() {
	remove_menu_page( 'index.php' );            // Dashboard
  remove_menu_page( 'edit.php' );             // Posts
  remove_menu_page( 'edit-comments.php' );    // Comments
  remove_menu_page( 'themes.php' );           // Appearance
  remove_menu_page( 'plugins.php' );          // Plugins
  remove_menu_page( 'users.php' );            // Users
  remove_menu_page( 'tools.php' );            // Tools
  remove_menu_page( 'options-general.php' );  // Settings
}
add_action( 'admin_menu', 'remove_menus' );