Lost sound after update

A few months ago I believe an update (I think it was "Windows Update V4"
according to my restore files), caused my sound to disappear. ALL my sound.
I have the Musicmatch Jukebox with SoundMAX digital audio as the playback
program . After the download, no sound whatsoever from my speakers, not even
startup sounds, game sounds, etc. When I try to play a song from my music
files I get a popup saying "Wave not supported" or something like that.
Looking into my audio device controls, it shows no audio driver at all.
When I restore to prior to the download, I get all my music functions back. I
now want to install SP2, but will have to update, including the V4 I assume,
before doing so. What is happening to my audio with the updates? Thanks
--
Face piles of trials with smiles...
Scooter