I decided to redo the hardwood floor in my second bedroom. I pulled up the carpeting and also found stains. I rented a large floor sander and started the task. The stains came out but you have to be very careful not to burn the floor if you sand too long in one place. I then put three coats of polyurethane down. I was surprised it came out so nice. If you do sand your floor, make sure you use a face mask because of all the dust. It is a lot of work, but worth it. I prefer the hardwood floors to carpet because they are so much easier to keep clean, especially with the new products out like "Swiffer".