If you cannot open the guest session and get a VERR_NOT_FOUND VirtualBox error, follow the tips, solutions, and workarounds mentioned below. Check if “VBoxGuestAdditions.iso”n exists Insert Guest ...
I don't think Virtualbox has a UEFI option, so I think virtualbox is (rightly) booting legacy. But still it can't boot from that ISO I just tried VMWare Player I notice that one can choose UEFI or not ...
Late on Friday, December 13, Valve released the first public version of SteamOS. As you would expect, SteamOS is currently very rough around the edges -- it is essentially just a version of Debian 7.1 ...