Make Tech Easier shows us how to get up and running with VirtualBox from a bootable USB drive. To do this, you'll need a bootable USB drive (obviously) and you'll need to be comfortable using command ...

Open VirtualBox Select the guest OS, but don't launch it. Click on the Settings button. Go to System > Motherboard > Boot Order Select an entry (e.g Hard Disk, USB, or DVD drive) and use the arrow ...