|May I further clarify the terminology. Cards are hardware which is inside the box (not software).|
If you can get a picture on the screen, then you either have a graphics card or, as in your case, inbuilt graphics - both are hardware.
If you can get any type of sound, then you either have a sound card or, as in your case, inbuilt sound - both are hardware.
Drivers (software) are necessary to make the above things work properly.
As this is a sound problem, then it is nothing whatever to do with graphics drivers or graphics cards. If it should turn out to be a problem with the software, then it is sound drivers that you need. Sometimes they are part of a set of chipset drivers.
I hope this helps because unless the terminology is about right and understood, then it will be very difficult for anyone to properly discuss this issue and give meaningful advice.
some other bloke...