Problems with installation?

All of a sudden, youtube tells me I need to update flash player - so i do. The installation starts, finishes, and everything seems fine. I click finish, it takes me to the adobe wep page that tells me I am now running Adobe Flash Player. However, I still can't watch videos, and all websites are still telling me to download adobe flash player. I've installed in around 5 times now and each time it seems successful but nothing changes! help!