Hello Jeebee,
I don't see any settings about my soundcard in my BIOS though, so I have no clue on how to enable it. Further, sound does work when I boot winxp...
Good.
Ok. Try this.
Change your /etc/modprobe.conf back to its original form then try this routine again and copy and paste all terminal output here.
$ /sbin/service alsasound stop
$ lsmod | grep snd
$ /sbin/service alsasound start
$ lsmod | grep snd
Look in
$ alsamixer
just in case (you need that 'Master' slider).
Also post your /root/scsound.log file after you do
$ system-config-soundcard