Manually removing/replacing audio drivers

Hi,
Does anyone know which files I would need to delete and replace – I think my audio drivers are corrupted and want to replace them.

I'm running 10.5.7
on Macbook 2.16GHz C2D

I currently am getting a message that no ouput is available.

Thanks

 

I'm not getting any sound at all. The sound preferences are reading "no output devices found" and same for input devices. Headphones don't work either.
It's weird because whatever has happened has also effected playback of flash files. They only play for a few seconds before pausing.

The last time the sound was working I had to force a shutdown so i'm guessing something not so good happened at that point. I've also done an archive and install of the OS.

... it could be a hardware failure but around the internet there's a few people with exactly the same problems so I'm thinking software issue might be more likely