Windows 7 - No Audio Output Device Installed

I have a Benq joybook s52 and I recently installed Windows 7 Ultimate on my laptop computer. Everything is working great, but I have no sound. In the bottom right corner, I have the audio icon with a red circle and a white x. It also says 'No Audio Output Device Installed'. When I look in the device manager, I have a yellow icon next to 'High Definition Audio Device' under Sound, video and game controllers, and I also have an Unknown Device under the Universal Serial Bus controllers. I've tried reinstalling the Realtek drivers and i also have reinstalling the device (digital_media_joybook_drivers_jbs52_audio_jbs52_audio_6.14.10.515), but nothing seems to be working. Can anybody help?

It doesn't seem like it ought to be necessary, but you could try installing the Intel chipset update for the 915GM chipset in your S52.

 INF Update Utility - Primarily for Intel® 5, 4, 3, 900 Series Chipsets

You said nothing about graphics, but here is what Intel has to say about drivers for "legacy" chipsets (including the 915GM):

 Older Intel® Graphics Controllers and Microsoft Windows 7*

Good luck.

I am still confused with your explanation, if I may ask for more detail, sorry for my forwardness, I'm very confused

thanks . .