Windows 7 No Audio Output Device Is Installed

[bioa10]

On the 23rd (three days ago) my sound was working fine, but saturday my sound stopped working and my speaker icon had a red dot with a white 'X' in it and says "No Audio Output Device Installed". I have gone into my device manager and the 'Audio, Video and Game Controllers' is missing. I have tried installing the toshiba audio drivers and it has not worked. Any help please?
Here are the speccy details:
Operating System
Microsoft Windows 7 Home Premium 64-bit
CPU
Intel Mobile Core 2 Duo T6500 @ 2.10GHz 59 °C
Penryn 45nm Technology
RAM
4.00 GB Dual-Channel DDR2 @ 399MHz (6-6-6-18)
Motherboard
TOSHIBA Portable PC (CPU) 53 °C
Graphics
Generic PnP Monitor (1366x768@60Hz)
Mobile Intel 4 Series Express Chipset Family
Mobile Intel 4 Series Express Chipset Family
Hard Drives
298GB TOSHIBA MK3255GSX (SATA) 35 °C
Optical Drives
MagicISO Virtual DVD-ROM0000
MATSHITA DVD-RAM UJ880ES
Audio
No audio card detected

 

[Saltgrass]

It is a little strange your Device Manager does not even show the entry for Sound, video and game controllers. That should be a basic entry. Have you tried using the View menu to show hidden devices. Maybe something is there.

Could you audio on the motherboard (I assume) have died? Do you have anything plugged in the sound ports?

Any bios options to enable or disable onboard sound?