this is the right section!

first disable ur onboard soundcard in BIOS.then try.mostly ur card will be enabled.else open a terminal as root user.try 'alsaconf' command.
terminal as root user:
in terminal(in kde,konsole),type after "$" prompt,
Code:
~$ /usr/sbin/alsaconf
^^ it will detect ur card and enable it.use kmix(in sound/multimedia menu) to adjust sound volume and properties.
if somehow alsaconf command is not available,download from mandriva website and install.I hope u already have ur internet configured on ur Linux Mandriva.