Realtek HD Driver update?

I have a Macbook Pro that has Bootcamp with Windows XP SP3. Everything works fine, however I would like to record system audio, which I can't seem to do. my friend told me to update the driver, however I can't find any new update. I have driver version 5.10.0.5772, codec ALC885, controler HD Audio. Does anyone know where I can get an update?