Whatever driver you are trying to install is not compatible with your hardware configuration. So, I went to the HP site and I don't see any Win8 compatible drivers listed:
What's compatible? You offer very few details in your opening statement and even less in your response. Now, you think its the other graphics card that is not working? You would have been better served if you first explained where you got the driver from, what version it was, and a bit more detail about your graphics cards so one would not have to go look up everything for you. Anway, I wish you the best of luck in getting your problem resolved so hang in there and someone will be along to help you shortly.