PCI Input Device Error

I am receiving no sounds out of either headphones jack (front or back).

I am wokring on a Dell Dimension XPS Gen 3 with Vista, sound card Creative SB Audigy 2 ZS (WDM)

I receive other Devices error ? - PCI Input Device (unknown) ! - drivers are not installed

I am then unable to reinstall the driver.

This desktop was formatted a while ago due to problems with performance and installed programs but this never affected the sound.

About a month ago, the computer was left installing updates overnight and on my return and restart of the computer the sound had stopped working. Initially, it was stuck on mute, and no amount of clicking 'unmute' would remove it from this state, until one morning I saw a faint flash of some driver re-installation, and on checking, the sound was 'unmuted' but nothing could be heard.

Now, when you double click the speakers icon and I have the radio playing in my browser, the green balance bounces up and down as if the computer is receiving sound and playing it back, however no sound comes out.

Any help would be greatly appreciated.

Regards,

John