The "Bootable" legacy ISO you've used is in fact not bootable, it relies on CDROM emulation provided by BIOS. VMs don't usually do this sort of emulation. If you set the guest OS to something like ...

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 ...

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 ...

If you're on Windows, need to use OS X, but don't want to buy or build a new computer, reader Bobby Patton shows us how to run Snow Leopard in a virtual machine on Windows with just a few tweaks.