Windows 7 NO SOUND!

Hello, thanks for your time in advance.

I have been using win7 pro 64 with my new system for nearly 6 months. I had no problems until now, but since the beginning of new year i have this no sound issue.
Appriciate your help.

i have gigabyte x58a-ud3r mobo and i used to have the sound coming from my monitor with hdmi output of my gpu (nvidia gefore gtx 460), i sometimes also use the audio jacks in front or the back of the case to get audio to headphones.

now i tried several options but what i get is this.

in device manager, i see no problems and sound cards look fine, i already updated it to latest realtek drivers after having the problem but no luck. when i go to dxdiag in sound section i see no cards listed and below its something written like "windows audio service disabled, go to services to enable it". but when i go to services.msc i have nothing related with sound in the list like "windows audio" or whatever. i tried deleting all the sound drivers and reinstalling, disabling the nvidia ones and just leaving the realtek or reverse. but nothing helped. when i go to control panel and click on "sound" nothing shows up either. when i click on realtek hd audio manager i just get a blank screen. it says "you are seeing a blank page because there is no sound device working on your system. to activate GUI, please plug a sound device"

I checked to see if there is anything in bios to be enabled. the only thing i see in bios about audio is "azalia audio" and its set to automatic. the only other way to change it is to disable it.

any suggestions please?