Try Vista drivers for your card.
Next try the XP drivers.

Beg Nvidia to fix their drivers for the game.

Try the game in Wine and see if it works there.

Beg Activision to release the source code.

Well, if Wine worked in reverse it might be helpful... (HG2 is Linux compatible)

Can anyone recommend a specific driver set that might work? There's loads to choose from.

The earlier the better as long as your card is supported by the driver.

For some games I run them in Vmware using Ubuntu as a guest OS and then I run the games in Wine. When the games work it's great but more often than not they don't. Can't remember if HG2 works in Wine.

i havnt tried heavygear 2 because the game insists on installing the ias sound system and im not sure if it will mess anything up.

I wouldn't worry Davros - I've had the game/IAS installed for around a week now, and haven't noticed any anomalies. (Well, other than all the transparent objects...!)