Need help installing Adobe Flash Player

I need to install Abode Flash Player in order to play some internet games on sites such as msn.com or pogo.com. When I go to install it, my computer says that it has successfully been installed, but when I go back to try and play a game, i get the same error that it needs to be installed. I figured there it has something to do with the system settings, but I don't know how to fix it. Also many websites do not make their games accessible to the Leopard OS and you must have Windows to play them. Are there any more websites I can go to to play internet games using the leopard OS?