I hope the following may help you.
After installing Vista SP2 the sound on my laptop stopped working. After fiddling around for some time without any result, I decided to download and install the latest Realtek drivers. Reboot and the machine tells me it is loading the new drivers. Job done but still nothing.
With nothing to lose I installed the drivers the second time (without uninstalling first). Reboot and everything is working properly again.
Why I had to install twice is beyond me, though I have a feeling that the first install just got the drivers going and the second got the Realtek software working as well.
Good luck anyway
