I have been searching for the driver for this:
System model: MICRO-STAR INTERNATIONAL CO., LTD KM266-8235
Main Circuit Board: Board: MICRO-STAR INTERNATIONAL CO., LTD MS-6738
Bus Clock: 100 megahertz
BIOS: Phoenix Technologies, LTD 6.00 PG 09/22/2003

I am very confused as to how to go about this. I thought I found the driver somewhere, but then I unzipped it, and tried to extract it but it won't work when I go to Device Manager to install it to see if it will work. When it asks for model I am not sure if it wants the model # of the motherboard or the system model. All this is baffling to me but I hate not having sound and cannot afford to take it somewhere to get fixed.
I appreciate any help in this matter (more then just 'here is the link' because I can't seem to make it work after that).
Thanks again,
Penne

Support Information:
Device Type: BIOS / Motherboard
Manufacturer: Microstar
Model: KM266-8235
Interface: Other
Operating System: Windows XP Home
Age of Device: < 6 months old
FCCID:

Find it on DriverGuide (http://members.driverguide.com/index.php?action=srch&sm=b&aax=&qa6=3196&qa5=1&qa7=1500&dp=0.5&qm0=KM266-8235&jmd=and&fzz=d) | Find it with Google (http://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=Microstar+BIOS+%2F+Motherboard++KM266-8235+Windows+XP+Home+) | Research manufacturer Microstar (http://members.driverguide.com/index.php?action=getinfo&companyid=3196)

hi there

first, FYI you could have gone stuck because of wrong classification.
this motherboard is called Microstar KM2M and based on Via KM266 + 8235 chipset.

Find out more: http://www.dealtime.com/xPF-Microstar-KM2M-Combo-L

Checking the specs further, you may notice this:
Integrated Audio AC97 Audio Codec • Realtek ALC650

I guess you gotta check official realtek site for further instructions since they always have updated drivers for every operating system.

BTW your mainboard's FSB is stated as 266Mhz which is normal for S462 - compilant Duron processors. Not any kind of 100 mehahertz you told us. (My Pentium III Coppermine features 100 mehahertz, i'm not sure you got the same :) )

Update : check this page for official drivers. I hope you wont be downed with russian. Guess you would understand where to click for download.
http://www.microstar.ru/program/support/download/dld/spt_dld_detail.php?UID=411&kind=1

(I also guess updating BIOS ROM will be a good idea)

Good luck.

This web page contains several links to ALC650 Realtek drivers: http://www.free-codecs.com/Realtek_AC97_ALC650_Audio_Codecs_download.htm