no sound

I have upgraded my windows to 7 64 bit and i found that my speaker no longer work so i purchased a sound card c-media for windows 7 64 bit and when i changed the sound card i am still getting no sound i have tried a lot of silly things like trying headphones and downloading different drivers but i think it,s a setting on my computer and have tried to change lots of them no joy anybody out there with a simple answer for me please?and try not to give me the run around by eliminating the obvious as i have tried all that before , i am loosing my mind HELP