Sound Blaster X-Fi XtremeGamer
and
ALC888 HD Audio
If you would try to install High Definition Audio, then it won`t recognize the driver at all.
Go to this page:
http://support.dell....oads/index.aspx
Select Drivers, then go to Choose Model: choose Desktops -> Vostro -> 200. After that from the Operating System list, select Windows XP and you`ll see 2 drivers (the ones I mentioned). Download first ALC888 HD Audio and install it. In case that one doesn`t work try the first one.