I recently built a new system with a DH77DF motherboard. Before installing Windows, I updated the BIOS to the latest version 100 using a USB stick. While trying different BIOS settings, I discovered that checking the Video Optimization box prevented booting into Windows. Fortunately unchecking it restored normal operation. Using Windows 7 x64, UEFI boot on GPT mode SSD.
Not a big deal, I can live without a second or two slower bootup, but it should be fixed.
I will report the problems that you are encountering when enabling the video optimization to the proper department.
Thank you for the feedback.