Your post is a little unclear where these drivers came from. We've learned that MSFT is not a source for said drivers.
Starting at http://h10025.www1.hp.com/ewfrf/wc/softwareCategory?lc=en&dlc=en&cc=us&lang=en&product=3740326& I see the Vista 64 driver there.
I have an HP m9340f with Vista 64 bit. Cannot install NVIDIA driver update. In device manager I click on OTHER DEVICES, it comes up Unknown device. When I open up properties to reinstall the driver(s) it says the drivers for this device are not installed. (Code 28 ) Access denied. This all started after the updates on Oct. 16/09. I also have Norton Internet Security installed on my computer which was installed on Oct.10/09. Any help would be appreciated. Thanks in advance.