Perhaps they referenced this guide to create a bootable Live USB on Windows, allowing them to test drive something like Ubuntu without making any changes to their PC.

How to make a bootable USB drive If you're trying to install a new operating system or flash your BIOS, you're going to need a bootable USB drive - here's how to make one.

Jesus Vigo shows you how to create bootable USB flash drives that are used to install just about any OS on your computer with the help of Rufus.

Jesus Vigo goes over the steps to create a bootable USB to install OS X 10.9 (aka Mavericks).

A bootable USB key is a convenient way to install operating systems on netbooks without optical drives, or carrying around a Live OS with you at all times. It especially makes sense if you're ...