Windows 7: No Sound, drivers installed fine

Hi i've been looking around on the internet about a problem that has happened on my new pc I built it myself and for the first few days the sound was working perfectly but in the last few days it has stopped working altogether, all the drivers are installed fine but neither WMP or iTunes play any music they just refuse, all the hardware is installed fine in the device manager and 'Sounds and Devices' i even tried a pair of USB speakers but they do not work either; I hope someone can help.
Specs:
Windows 7 Home Premium 64bit
GA-P55-USB3 (W/ Realtek ALC888)
Intel Core i5 750
HD 5750

Thanks Charlie

Be welcome to SF!
Did you check audio configs at Realtek Control Panel - orange speaker next to Windows clock?!
Wrong config "kills" sound outputs!
Take a time to test some o' them and let us know the results!

"PLEASE REP ANYONE WHO HELPS YOU"

Does the green volume indicator in Sound > Playback Devices show any reaction?

Thanks for the reply yes i have tried using the realtek control panel i have tried everything in it but with no avail it even recognises an audio jack plugged in but no sound comes out.

Nope it does not have any reaction to any playback, windows wont even let me play a test tone it says "Failed To Play Test"

Try: right click on My Computer > Manage > Device Manager > sound, video and games drivers > right click on Realtek HD Audio> uninstall. Reboot and let Windows reinstall the device. Test whether there is sound. If so, install the Realtek driver 2:47, which is found here: Realtek

Let us know the results.

"PLEASE REP ANYONE WHO HELPS YOU"

One thing you didn't mention and no one asked, is the Realtek set as the default playback device and not the ATI HDMI Audio (from your video card)?

thats a good point stormy13, a quick google finds many instances of the sound defaulting to the graphics card ,so that is definately one to check also check in the bios that the onboard sound is set to enabled and not auto

Thanks for the response, nope i have tried this but it still does not work.

My speakers which is the realtek HD Audio Device is the default playback device

There is no option for audio in the BIOS so i assume its on

in the bios where it says Azalia codec check that its not set to auto , do you have the mobo manual if so have a look at page 50

I guess you might want to check and make sure you're set to stereo output.
Same place where you see Speakers as the Default Playback Device. Select speakers and then use the "configure" button.

And your speakers are plugged into which color output jack?
Stereo is "light green" but for a few it seems to be black.

Also, you didn't by any chance disable some "services" recently.

Ap