Audio Gone

I was playing a game, when the sound suddenly went away.

Here's my specs (says Speccy):
Motherboard: ECS GeForce6100PM-M2
OS: Windows 7 Ultimate 32-bit
Audio: No audio card detected

My PC is 4 years old I think. In the device manager, the "Sound, video, and game controllers" is missing. The Realtek HD Audio Manager cannot be seen on the system tray. The audio on the lower right has an 'X' mark and when I hover over it, it says "No Audio Output Device is installed". If I click it, it tries to detect problems.

I tried uninstalling and updating Realtek HD Audio Driver. And I also tried the Windows Audio on Computer Management solution. Either solution won't work.