When you download the audio driver, what procedure did you follow?

Here's what I recommend (usually);

To install drivers from the internet:

go into Windows Explorer, left click on Desktop, then File, then New and then Folder - name the folder XXXDrivers (where XXX = type, eg, AudioDrivers)

go to the site for your driver, find the RIGHT one for your mobo and OS,(click on the nearest site to you if appropriate) and then download button - when asked where to 'save' the download specify your desktop folder XXXDrivers and wait until the download is complete.

Once it is done, clear your screen and click on the desktop folder and then on the file inside - if it is a zip or rar file it will need to be unzipped or unpacked - make sure if you are asked to specify where to unzip/unpack to tell it to do so to the XXXDrivers folder.

Once you are done that, uninstall the old drivers for the device and then select the device and specify update drivers and direct the search to the folder you made (don't let Windows do it).