Movie maker codec...please ?

okay. i have a casio elixim 10.1 megapixel camera. i have been filming drum covers. and i really would like to edit them on movie maker to have back tracks and clear up any other problems. but when i try to import the videos from my camera, i get an alert that says my computer doesnt have the right "codec" installed in order to use the video file. so i went to microsoft and downloaded the latest codec. then i closed movie maker, like it suggested, and then reopened it. but i still got the same alert. WHAT DO I DOOOOOOO!!!!!!!!!!!!! i have no idea how to fix this problem. please help me out...thanks guys.