Howdy...
Hopefully we can get this figured out. A few things:
1) don't mean to insult your intelligence but, is the volume muted and if you have external speakers plugged in, are they powered on and is the volume up?
2) Is this with CD's, mp3's and internet, or just internet?
3) if you have "This PC" on your desktop, right click and choose "Manage". In the left pane, look for "Device Manager". Click it. Scroll through the options until you see "Sound, Video and Game Controllers". Expand it by left-clicking on it. You should see at least RealTek. Is there a black arrow on RealTek? If so, it was disabled in the update. Simply right-click and choose "enable". Then test for sound.
In a little while, I'll post a screen capture video walking you through the steps.