Installing Windows 8 x64 and Debian 7.1 (Wheezy) x64 (old)

I have some problem using Windows 8 x64, for short of period, I need to update my windows with up to 2 GB files to download. It is unstable, that is way I decided to make dual Operating System in my Laptop.

Windows 8 x64 was installed on GPT (GUID Partition Table) and Secure UEFI (Unified Extensible Firmware Interface).

My Laptop is Asus K45DR with AMD Processor with dual Graphic Processor.

First, I installed Windows 8 x64, install its driver, and you will get your screen flickering until you update your catalyst and Windows.

My first try to install Debian 7.1 was off line. And I failed during Grub2 installation process. I search using Google about a week how to fix it, but I can not find any solution.
I tried another way to install Debian 7.1, I stil use 1 CD for installation process, but I let Debian 7.1 x64 connected to Internet during installation. And at final section of installation, there is no more error on Grub2 installation.

Note:

Install Windows 8 x64 first on GPT using DVD/USB

Boot via EFI DVD and Install Debian 7.1 AMDx64 and let it connect to Internet during installation