You may still have a working sound system. That error may just tell you that it doesn't support surround (not sure about that).
To test the sound system, of course, make sure that speakers are connected correctly and turned on and so on...
Then find an .au file. Older distros used to include an au file where Linus tells us how he pronounces "Linux".
You can download it from
here.
Save the file to your home directory, open a console (shell, terminal, whatever), change the directory to your home folder or where the file is and type:
cat english.au > /dev/dsp
or
cat english.au > /dev/audio
You may hear sound.
Also, check the mixer settings. You will find kmix by clicking the star button (Start if you're used to M$ windoze), Multimedia, Sound, then Kmix.
Play with the mixer, you may find that the volume settings are not right by default.
If you still don't get sound, you may have to post some logs.