When it comes to modernizing a room with a chair rail, there are several things you can do. First, consider painting the chair rail a different color than the walls. This will help create a more modern look. Second, add some wallpaper above the chair rail or use paint to create a unique design. Third, choose new chairs for the room that have a more modern style. Finally, accessorize the space with modern décor items such as vases, art, and rugs. By following these tips, you can easily give any room with a chair rail an updated and fresh look.