The USB flash drive has replaced the floppy disk drive as the best storage medium for transferring files, but it also has its uses as a replacement for CDs and DVDs. USB drives tend to be higher in capacity than disc media, but since they are more expensive, they cannot (yet) really be used as a replacement. There are reasons why you would, however, choose a USB device over a DVD disc, and bootable software is definitely one of them. Not only is it faster to copy data such as setup files from a USB drive, but during usage the access times are also significantly faster. Therefore, installing something like Windows 7 will work that much faster from a USB drive than from a DVD (and of course, is particularly useful for the PCs without an optical drive; this isn't something we should just leave for the pirates to enjoy).
This guide will show you two different ways to create a USB flash drive that works just like a Windows 7 DVD. In order to follow this guide, you'll need a USB flash drive with at least 4GB of free space and a copy of the Windows 7 installation disc.