i have downloaded via ac'97 enhanced audio controller driver for linux with kernel 2.4.0. i don't know how to install the driver, need help. thanks!

Just a question, doesn't ALSA works with it? You'll have less problems if you use it
Run: alsaconfig (as root) to see if it's detected.

not yet. ok i'll try. but if it works is it ok even if its not the right driver?

If I'm not wrong ALSA has a driver for it (I'm 99.9^% it has one), so i'll be fine, that's the porpuse of ALSA, bringing you all the drivers you need for sound

Couple of questions here. What soundchip does your board have,
or do you have a separate soundcard? You should be able to
get this information by issuing, as root, "lspci" and something like:
02:0b.0 Multimedia audio controller: Creative Labs SB Audigy (rev 03)
will be your soundchip.

Do you have any sound at all? Have you issued "alsamixer" as a
normal user? Do this and turn up the volume on Master and PCM
and see if this gives you sound. You'll also need to use the M key
to unmute anything that's muted. After you run "alsamixer" then
you need to hit ESC to exit the mixer, and then login as root and
run "alsactl store" to save these settings.

Are you running a window manager or desktop environment? Say,
Fluxbox, KDE, Gnome, etc? They all seem to handle sound a little
bit differently, i.e. different sound servers, so if you'll add that info
to your post it will help people give you some answers.

thanks a lot guys! it works perfectly and easier than i thought. its actually easier than installing the driver in windows.

Nice to hear that
Can you post what you did so others users can see at it? Thanks.