Could you post a belarc advisor log on the page so we can verify what type of sound card you are running.
In the meantime you could try and boot into safe mode, go to device manager and remove anything under the sound card list.
Then restart your machine. It should ask for the drivers but they are normally installed into a directory on the machine which windows should find. If not try tell it to go to c:\windows\system32\drivers or do a search for the specific file that it is looking for.
You can get belarc advisor here :
http://www.belarc.com/free_download.html