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.

If you choose to create a bootable USB stick, you have to use a dedicated piece of software such as Universal USB Installer or Rufus. Otherwise, you have to burn the image to a disk Boot to live ...

Create a bootable USB stick from Linux I was keeping the best for last. If you are running Linux, you can use the dd command (as in the instructions for macOS above) to create the bootable drive.

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.

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 ...

Another even simpler way involves creating a bootable USB flash drive with a fully functional copy of Ubuntu installed.