Windows 7 x64 - No sound output

I had this problem once when installing Windows 7 on my laptop. I installed the drivers from Windows Update and Dell for my sound (C-Major audio). What the problem was, the mulitmedia audio controller was not installed. I was lucky that I had a driver disc that had this on it. If all of your audio drivers have been installed with no results, this may be your problem.

Hm...I don't see any separate driver for a multimedia audio controler. In the Device manager, the only thing in the audio controler category is "Realtek High Definition Audio" which I've already uninstalled and reinstalled a few times :s

If I'm not mistaken, it's not a driver, but a piece of software (the multimedia audio controller) that I was referring to. But if that were the case, it would show up as being the problem during troubleshooting. It's been awhile since this happened, but when I install 7 on my laptop, I have to pull out my driver disc to load the device. Win 2K & XP Pro doesn't do like this, but the laptop was built in 2005. I was hoping this would be the answer for you, but the answer does lay somewhere, and I'd guess that it's a simple one.

Had this happen to SPDIF over HDMI output on my Dell XPS laptop a few months back. Sound simply disappeared after a windows update. A system restore solved the problem, and subsequent windows updates did not affect the sound...

Since yours is a fresh install, I am at a loss for what you can do about it.

VeNoM, the system restore solution might work for you. It's worth a try.

Well...I did try to use the system restore, but for some reason it said I couldn't access the file and to try to disable the antivirus....which I did, still didn't work, in the end I tried so many things that now I don't even have a good restoration point anymore :/
It really is strange...the sound worked for 2 weeks without any problem then...after a windows update (or maybe a flash player update ? Oo which would be even odder) ....poof no sound >_>

I fixed the sound bug : I uninstalled all windows updates, Flash and my sound drivers and then let Windows update install everything back then I restart the computer.

Glad to hear that worked out.