If they're realtek you should have an orange "Realtek HD Audio Manager" icon in your bottom right taskbar (may need to click that little up arrow to see it). Open that, is the green "back panel" port lit up as in the pic below?
Also, if you just click once on the Sound icon in your taskbar (the black and white outline one not hte orange realtek one) does it say "Speakers (Realtek High Definition Audio)"?
"As a result of all this hardship, dirt, thirst, and wombats, you would expect Australians to be a sour lot. Instead, they are genial, jolly, cheerful, and always willing to share a kind word with a stranger, unless they are an American." -- Douglas Adams