Me parece que debe ser uno de estos:
REALTEK HIGH DEFINITION AUDIO VERSION R2.31

Vista (32/64 bits)& Windows 7 (32/64 bits)
http://www.mediafire.com/?yntgnorwnlg

Windows 2000, Windows XP/2003(32/64 bits)
http://www.mediafire.com/?knjmmztjylt

Driver Package R2.31
Realtek HD Audio Driver support all of Realtek HD Audio Codec .
1. Vista/Windows 7 WHQL Supporting: ALC882, ALC883, ALC885, ALC888, ALC889, ALC861VD, ALC660, ALC662,
ALC663, ALC665, ALC260, ALC262,ALC267, ALC268, ALC269, ALC272, ALC273, ALC887,ALC670, ALC275
2. Windows 2000/XP WHQL Supporting: ALC880, ALC882, ALC883.....

Fuente:
http://www.taringa.net/posts/downloads/5594814/Realtek-High-Definition-Audio-Driver.html