I cant download anything on my pc

Hello,
i am having problems on my computer because every time i try to download something instead of just downloading it

to my computer it brings up the open with box and gives me the list of programs i open things with even if the thing i

downloaded doesnt need a program like itunes, and the only thing i can do is pick one and of course if it doesnt need

one it doesnt work. i have a pc


please help i cant download itunes for my ipod touch