No Audio Device Installed

Good morning everyone. I'm new here, but I've been lurking for the past few hours. And I haven't found any answer to my current problem in related threads. It's driving me crazy.

Basically, sound worked fine one day, gone the next.

Now, I'll assume you'll need my specs and such. Or, I can just give you a report via Everest. I'm not too computer savvy, so finding out all the details of my computer on my own might be a tad bit slow and messy. I hope that's the right report. >.o;

Also, in the 'Device Manager' I seem to be missing anything that has to do with Sound, Game controller and what not. And the whole click 'run' then run the 'regedit' didn't work for me either. Any other ideas, dears?

Here's the basics, I assume;
Acer Aspire 7520
Microsoft Windows Vista Home Edition
Service Pack 2

And, it's a laptop. So I know nothing got unplugged.
I hope.

 

Im not to sure about why its not in Device manager but this is the driver you will be needing

Here is a link to the drivers you will need
http://support.acer-euro.com/drivers/notebook/as_7520.html