So the problem is i can't change boot device to be exact. I had a 80 WS HDD and had it installed on SATA 0 slot and bought another HDD later for sole purpose of windows 40GB (don't want windows to go over 40 GB, need to only basic things on this drive) and had it installed on SATA 2 slot on SATA 1 slot there is my dvd writer. So Since only my sata 0 slot has the transmission speed of 3 Gb while the rest of the slots have 1.5 GB i wanted to change the 40 gb drive (windows drive) to sata 0 but when did it the pc says no boot device detected. It is because windows 8.1 only run on the slot i installed the window from, this does sound stupid but that's all i think.