I installed a c-media driver update from windows update and lost sound completely and now i have tried reinstalling the original drivers that came with the motherboard but that doesn't even work

System board is an asus a7v8x it has a via chipset and the onboard sound is ac'97 audio

Possibly System Restore?

or:

Roll Back Driver via Device Manager?
start/run/ devmgmt.msc

or:

ASUS site:

http://support.asus.com/download/dow...Language=en-us

Navigate: Motherboard | Socket A(462) | A7V8X | Drivers

Uninstall the current drivers before updating.

Or from VIA:

http://www.viaarena.com/default.aspx?PageID=2&Type=1

Audio drivers depend on specific chipsets.

Also might want to update the Chipset with the latest 4in1.