virtualbox.org

Hi, I'm running on Windows Vista x64 bit.
I'm trying to make a drive so that I can load up multiple things that my computer doesn't allow me to with just itself.
But, when I go through the tutorial, and click run, it says on the black screen "FATAL:No bootable medium found! System halted."

Help please?

Have you mounted the OS that you are trying to install in the guest setting and section CD/DVD?