SOLVED! :-D
Something so stupidly simple...
The motherboard CD didn't install the AGP drivers automatically along with everything else. They seem to be tacked on to the end of the cd with no way to get them from the main installation/menu.
Installed, rebooted, "Found new hardware" :-D
The wierd thing is, I don't remember having to install the AGP drivers a few months ago when we got the mobo and gfx card.
@blob
I've installed 45.23 at the moment (it was the quickest I could find), I'll install 56.72 and DX9.0 tomorrow (DXwebsetup doesn't want to work just now and I'm going out again tonight)
@mikey and Ilwrath
Cheers anyways :-D Guess this means I don't have to write down the menu system for my bios now :-D
/me thankfully wipes brow :-D
The annoying thing is I won't have time to play HL:DoD until tomorrow now :-( but at least I'll be able to play it :-D