As usual, I apologize in advance if someone else asked this before althoguh I've checked the forum but couldn't find something (exactly) similar to solve this. I have 2 laptops, one with windows 7 installed in its internal drive and an external usb drive with ubuntu 14 installed in it, connected all the time to pick whichever os i'd like to boot up with via grub2. (by the way grub2 shows up most of the time but still occasionally windows boots up directly, bypassing grub2) The other laptop is just windows 8.1 in its internal drive. Problem is, when I try to connect this external drive with ubuntu to my second laptop with windows 8.1. Its a sony vaio, the boot menu could only be opened if you switch on using the assist button. I did, then changed the primary harddrive to external usb harddrive with ubuntu but it just doesn't see it. Could someone please shed some light on this ultra-mega-hiper noob problem? I though installing grub2 into my second laptop but that seems not necessary given that it works from the external when connected to the other laptop.