Rufus is a free software (GNU GPLv3) that can format and create bootable USB flash drives. So I’m going to recommend another tool which works great and have no problem. Last time, I wrote an article about how to create bootable USB with UNetbootin which is a good tool, but there might be some issue with large image file (NTFS file system). If you want to reinstall operating system on your PC or laptop, you can install it from USB flash drive which is very easy and faster compare with optical drive like CD, or DVD.
