NFSU2 backing up saved games

my NFSU2 has been acting really weird since yesterday. the only button that works is Mouse1. even enter/escape on the menus dont work. when i try to us the Analog sticks (on my Logitech Dual Action) the menus freak out and scroll all the way to the left .teh weird thing is that when i configure my gamepad in the game, all those buttons work oO

so, i just want to back up my game, and uninstall/install it. i've looked around and i dont know which files to back up. any help on that? or perhaps how to fix my problem..