Sound card driver on MX6420 Notebook

I format my laptop last week and I reinstall another OS then the one
supply by Gateway. The latop came with XP Home edition and I reinstall
XP Pro.

But I wasn't able to reinstall my sound card driver, I look on Gateway
support, and I donwload the driver they suggest D00377-002-001 which
is for "Conexant AC-Link". So I wrote to Gateway support
center and they answer me they don't give any support if I've
reinstalled another OS, So I format the laptop again, but this time
with the original CD given with the Laptop: "Gateway system
recovery" with the OS XP Home... But again, my sound card wasn't
working at all. So I rewrote to Gateway tecnical support. They told me
to try to reinstall the driver D0377.... in safe mode bu making sure
that any other audio or game controler driver were uninstalled, what I
did.... but again, nothing is working....

I looked over the internet to find out another driver and none of
those I tried were working....

The sound card is suppose to be good, because it was working fine just
before I format the laptop... and I really don't understand why it
hasn't work with the original CD.....

I looked at my configuration with Everest and my sound card is:
"Conexant CX20468 @ ATI SB400 AC'97"

I really need help on this... I work on this for a couple of days now,
and I get no morew idea to try...

Thanks in advance