Description of Win32 Disk Imager
This is a Windows program for saving and restoring images from removable drives (USB drives, SD Memory cards, etc). It can be used to write boot images (i.e. ubuntu-12.04-preinstalled-desktop-armhf+omap4.img) to a SD Flash device or USB flash device, making it bootable. Newer examples are operating systems for Raspberry Pi.
Win32DiskImager supports writing an ISO image to USB too, which is very valuable right now with the Ubuntu releases 14.04 LTS - 15.10, because there are problems with the Ubuntu Startup Disk Creator.
The program and source code can be downloaded from here.
You can find also a self-extracting exe file, that helps you install Win32DiskImage, via this link to the archive, sourceforge.net/projects/win32diskimager/files/Archive
This tutorial subpage with screenshots illustrates how to create a USB boot drive from a Lubuntu ISO file. It works in the same way for all current Ubuntu family iso files including the Ubuntu mini.iso version 14.04 LTS (but mini.iso version 12.04 LTS is the only exception).
This tutorial subpage with screenshots illustrates how to create a USB or SD boot drive in order to boot a computer or device from an operating system in a compressed image file.