Grr I had this exact problem on my laptop but I can't remember how to fix it... I'll be back later if I remember!
EDIT: Never mind, I remembered.
First thing to do is go into Device Manager and find Sound, Video and Game Controllers. Delete whichever entry relates to your onboard sound (Audio Deck in your case). It should be gone from the list and then you just reboot, Windows should detect it again and hopefully install suitable generic drivers. Or if you have the latest drivers for that card you can just install them yourself.
Also try going into Control Panel > Sounds and Audio Devices and click the Audio tab. If your onboard card shows up in the dropdown boxes Sound Playback and Sound Recording then at least you know it's detected and that Windows thinks it's working. Also check the Volume tab and make sure everything is set up correctly (including your speakers).
Obviously also check your speakers are on and turned up (that they're plugged in to the correct socket), and that none of the slide bars in your volume control are ticked or set to the lowest settings.