Windows 7 Code 21

[Gog Llundain]

Hi All,
Running the Windows 7 Ultimate now and only one issue to do with my graphics card. I've seen similar posts here but no resolution yet. Here's my setup:

Windows 7 Ultimate (32 bit) running on a Shuttle ST20G5. I've flashed to the latest BIOS (but that was released in 2006!)
GeForce 7600GT

I'm able to run Windows using the onboard graphics card but I'm not getting a very good Windows Experience Index. The graphics card gives me a 2.0 so you can appreciate I'm keen to get my GeForce running.
Windows seems to recognise the GeForce card and I can install drivers for it but it reports this error message in device manager:

This device cannot find enough free resources that it can use. (Code 12)

I know this is to do with IRQ, memory addresses etc but I can't find how to diagnose/resolve the issue. I thought my days of manually changing IRQ settings was behind me... I've tried changing some BIOS settings including disabling some of the other onboard options (like the audio) but I still can't get the graphics card working.

Well, bedtime! Looking forward to your replies,
Gog Llundain

Edited:
I've done something a bit useless! I've been messing around with BIOS settings again in the hope that the resources will be automagically reassigned but now neither the PCI-Ex graphics card nor the onboard one works. I get 4 bit colour with both

I've also found some interesting threads like this one but this hasn't solved my problem either (though it has for some people).

 

[Gog Llundain]

Code 12 (not 21!)

Hiya,
Realised I quoted the wrong code number in the original title. D'oh.

Reflashed my bios with the image from this page and that has solved my issues.
My Windows Experience Index moved from 2.0 to 4.5 (my RAM is letting me down now).

Regards,
Gog