[dba-Tech] Sound Card

Dear List:
 
I had to reformat the hard drive of one of my kid's computers.  Pretty much
got it reloaded - Windows XP SP2 - but - no sound.  No device installed.  
 
It's an HP Pavilion a1221n.  And I don't have the restore disks or the
documentation so I don't know what sound card is in there or how to install
it.  
 
Any ideas on how to proceed?  Short of opening the box and looking - what
kind of sound card is in there, how to install it, update the drivers, etc?
 
MTIA,
 
Rocky