Thanks for reply my post. I've disabled the integrated video card. But the problem still persist. Actually I've solved the problem yesterday. But sorry I forgot to post that the problem was solved.
I update my BIOS, then it can recognize my video card. So many of problem was solved, not only the video card, but also the lag time during booting (since I used SATA hard drive as my storage, it almost take 30 minutes to boot). And now my problem solved.