Sound Not Working After Downloading Windows Update

So my computer has been downloading and installing the service packs and updates for Windows Vista. But now the sound doesn't work on my computer, it will work for the first couple minutes after I turn on or restart my laptop, but it goes out after.

I did a search on google and apparently this is a common problem but after following the directions to fix it and even downloading their program to automatically fix it, it still doesn't work.

Any help?

 

I have a Sony Vaio Laptop. I haven't tried reinstalling the driver because according to the windows website, the driver is installed and working properly. I'm not very computer savy so I really have no clue on what to do.