Sound Driver Problems, ALCXWDM.SYS?

I've had some sound problems, and I'm 99.9% sure that my sound driver is the source of my problems. Under my Device Manager I found 'Multimedia Audio Controller' which had the yellow '?' symbol. I did a little bit of research and found that people with similar problems had this, too. So, I went to Realtek and I downloaded the necessary files and "Multimedia Audio Controller' went from 'Other Devices' to 'Sound, video and game controllers.' The only problem was, now it had a little '!' and told me it was out of date. In trying to update, I was prompted that I need ALCXWDM.SYS. I did some more research and found some conflicting reports about the file, some saying it was great and others saying it caused crashes. Is the file safe? If so, where can I download it? Will it fix my computer troubles?