Ah, so near so far... If I try to play an MP3 or view a video it says that it's in a format that is not supported, and when I click on the Playback devices I get this error again:

33821

EDIT:...

Never mind. I'm an idiot. I didn't realise the link in step six of post #14 was in the post. I was using the link in the original post. All working now. Many thanks.

As per "My System Specs" I have an ASUS M4A78-HTPC motherboard which has integrated VIA HD audio (I assume that is what you mean by "audio chip"?

I have twice followed the instructions in post #14...

I've installed the new drivers without issues but I'm still not getting any sound :(

I have Speakers selected as the playback device but no sound is produced.