Hi, Kevin,
I have a similar problem, and I've seen numerous references on various web forums from others with related problems. I have a Gigabyte Z87X-OC with a 4771 using on-board HDMI video with a single monitor running W7-64. (The board has no DVI out.) Installing the HD4600 driver results in no-boot, which can be cured by removing the driver to use the generic VGA driver. I can hardly believe so many people have hardware problems; this seems to be a flaw in the driver. Any ideas?
Greywolf