udah gan ganti semua installer windowsnya alhasil gue pake method ini http://huguesval.com/blog/2012/02/installing-windows-7-on-a-mac-without-superdrive-with-virtualbox/comment-page-3/#comment-11433 dan akhirnya work juga install windows 8.1
duh stuck bgt nih install windows 8.1 via bootcamp usb padahal dulu lancar jaya skarang jadi gagal mulu message errornya kalo ga "Windows could not update the computer's boot configuration. Installation cannot proceed" pas terakhir install atau gak "partition can't be used because i