Thanks but after contacting the seller, I have confirmed the card was already set to use the good BIOS, which is the factory BIOS it shipped with. He said if the incorrect one was set it wouldn't even boot.
He did suggest some beta drivers to try but these have made no difference. I have also tried completely removing all traces of previous display driver installations both manually by deleting files from the locations and registry and with the display driver uninstaller tool as well but none of this helped, I am still getting code 43 in device manager.
I also tried running a benchmark (unigine heaven) to see if it was working at all but I just get a black screen with the mouse pointer so it looks as if all the cards 3D features have been disabled for some reason.
Does anyone have any further suggestions for fixing the card?
Alternatively is there any good diagnostic software for graphics cards that might be able to tell me exactly what is preventing the card from working?