hi all i was haveing the same problem with mine after instaling xp i had no sound so i went looking and found some one that know what he was talking about on the net and i now have sound on my windows xp if you need help contact me
or look for Conexant_HD_Audio_27320D_XP it has everything you need in it after installing it will come up with new hardware found and so on i then backed up my drivers with DriverMax Pro 5.0 so i dont have that problem again Driver max pro can be found here
http://www.phazeddl.com click on apps and do a search hope this helps you if you have any questions fell free to contact me at
traceyanddavid3@bigpond.com