Been trying to figure out why Windows 8 won't let me install this driver even when I go through the startup settings and disable driver signature verification and finally I got it. I found a clue when someone suggested on another forum some codes for disabling driver signatures using the command prompt: when I tried it it mentioned the option being against secure boot policy.
So if you are having this problem and cant install the Qnix driver (which will allow your custom refresh rates to show up in fullscreen games)--
All you need to do is put the boot mode to Compatibility and turn off secure boot. THEN you can get windows to listen when you tell it to stop with the driver verification signature. If I'm not mistaken, people have to pay to have their drivers verified... thus why microsoft really doesn't want people installing unverified drivers.