I've looked through all the related questions and done some searches and couldn't find a duplicate, so I'm pretty sure this isn't one.
I have a machine that has 512MB of RAM, and can boot from a CD drive. I want to run Windows 8 on it. This is not my main computer, and no it cannot have 1GB of RAM; please don't tell me not to try to run Windows 8 on it or that it will run badly.
On my main computer, a Mac, I installed the Windows 8 Consumer Preview .iso into a VirtualBox virtual machine, while the virtual machine had 1024MB of RAM, and then brought it down to 512MB after the install and it works to my satisfaction. I now have a configured, installed copy of Windows 8 on my .vdi file. I want to write this to the hard drive of my older laptop with the 512MB of RAM.
I can't find instructions to write the .vdi file to a real media (say, a flash drive). I know that a .vdi file also holds a partition table, etc…, but don't mind over-writing the flash drive. I would expect there would be a way to format the .vdi image (say, with VBoxManage) into a .img file which can be written to the disk with DD (possibly passing it through a .vmdk file or QEMU).
Once I have the image on the flash drive, I can boot the laptop from a linux live CD and DD the contents of the flash drive onto the hard disk, and then resize the hard disk partition, so if you can get me the .img image or flash drive formatted, I think that's good. I also accept other ways to get it onto the laptop hard drive (although I can't remove the hard drive, so installing Windows 8 on another laptop using that drive is out) or ways to do a fresh install on the laptop itself bypassing the system requirement check.
EDIT: The laptop doesn't have Windows installed, by the way.