I personally use free ImgBurn tool for all my ISO, CD or DVD related requirements. The only thing it lacks is a feature to create a bootable USB disk from a bootable ISO image of a CD or DVD. This is where Rufus comes in. Rufus is a simple free utility which makes it easy to create bootable USB disks from ISO images. Rufus works with all kinds of USB memory devices like USB pen drives, USB keys, USB hard disks, USB memory cards and so on.
Rufus is specially useful for those who do not have any optical drive on their system. They do not have to create a bootable CD or DVD to boot from. And even if they create a bootable CD using a tool like ImgBurn, it is going to be of no use as they do not have any optical drive. Owners of such systems can create a bootable USB disk using the same ISO and boot from it. Pete Batard, the creator of Rufus, claims that Rufus is twice as fast as other well known bootable USB disk creators.
You can download Rufus from the website of Pete Batard. The download is a mere 420 kilobytes in size. It is a portable standalone application and you do not require to install anything. Just double-click on the downloaded file and Rufus would be running. It is not necessary that you attach your USB key (or other memory device) to your computer, before running Rufus. Rufus can detect any USB memory device as soon as you attach it to your computer.
After you attach your USB memory device to your computer, Rufus would automatically determine its filesystem, cluster size and capacity. If you have more than one device attached, then you can select one from the drop-down list labeled Device. You can also choose to format your USB memory device and decide if you want a full format or a quick format. To create a bootable USB disk, you must selectCreate bootable disk using checkbox. Then click on the CD icon next to this checkbox and select the ISO image file you want to create bootable USB disk from. Now you can click on the Start button to start the process of disk creation.
This would show a warning that all your data on the selected USB disk is going to be destroyed. If you click the OK button, then the process would start and will begin by formatting your selected USB disk. Then it would extract files from your chosen ISO image and copy them to your USB disk keeping the folder structure untouched. In the end, it would make the USB bootable by reading the boot code from the ISO image (if the ISO is not bootable, USB disk will not be bootable either). That’s it! Now you have a bootable USB disk created from an ISO image.