No Sound in Windows 7 64-Bit

I have no audio in my computer. No sound from anywhere let it be Winamp, Windows Media Player, Youtube, system sounds, etc.

-Sound is NOT muted.
-Rebooting has not fixed the issue.
-I installed and reinstalled the Realtek HD Audio driver.
-System restore didn't fix the problem.

There was an error screen one time when I tried shutting down my computer, but it disappeared before i could see what it said and on the next boot up, there was no sound.

Everything in the computer says that the driver and sound is working. When I try to configure the speakers, it just says "Failed to play test tone."

Someone told me to enter the BIOS to check for audio...not too sure how to enter it. When I press F2 to attempt to enter the BIOS, it just takes me to setup and there is no option to check for audio devices or anything. It just tells me things about booting up.

I have a Sony VGN-FW510F/B. Realtek soundcard.
Also I have no Realtek Audio Manager no matter what version of the Realtek driver I install.

Thanks in advance!

Uninstall the Realtek in the Device Manager (but not the drivers) and then restart the PC and Windows will detect and reinstall the sound. This fixes a lot of flakey problems and may fix yours.

To access the Device Manager, hold the Windows key down and press the Pause/Break Key. The Device Manager can be accessed from the list in the upper left of the Panel that comes up. In the Device manager RIGHT click on the Realtek entry (to highlight it) and then LEFT click on "Uninstall". Restart the PC.

Also see if when in Device Manager you have any exclamatoin points on your Audio device.

"Uninstall the Realtek in the Device Manager (but not the drivers) and then restart the PC and Windows will detect and reinstall the sound. This fixes a lot of flakey problems and may fix yours."

Didn't work.

There are no exclamation points in Device Manager.

I've tried the speakers built in on the laptop - those don't work.
Plugging in external speakers or using headphones leave me in silence too.

Now my webcam and microphone don't work. I went to troubleshooting but they couldn't find any problems.

Alright updated. Let me know if I need to add anything else. :X

Thanks for the help guys.

This has happened to me twice, the first time I assumed the sound card was faulty so I bought a new one. The second time I figured something software related was going on! Both times I installed winamp (which I have used since it was first released without any problems) on a Win7 box with Itunes and media player installed.

music files payed normally, the sound bar on the volume control inicated that sound was being produced but nothing came out of the speakers or headphone socket as though it was muted, it was not!

The only fix I have found is use system restore to go back to an older version, eventually you should be able to restore a point where the sound works.