What is the easiest way to convert a USB device to a bootable device?The simplest way is to convert an ISO image to hybrid ISO by using syslinux tools and write this ISO fileontoUSB device. Almost all Linux flavors works with this procedure.What is syslinux?SYSLINUX is a boot loader for the Linux operating system which runs on an MS-DOS/Windows FAT filesystem. It is intended to simplify first-time installation of Linux, and for creation of rescue and other special purpose boot disks. http://www.syslinux.comIn simple words, these guys know how to boot Linux CD-ROM when we want to install Linux. Syslinux provide all the tools required to create a bootable device such as isohybrid, isolinux etc.Steps to configure USB stick as bootable deviceStep1:Install syslinux package on your machine, if it is not present.On Redhat/CentOS/Fedora based machinesyum install syslinuxOn Ubuntu/Debian based machines:

apt-get install syslinuxStep2:Get your ISO file from Internet or create one from a Linux CD. We can create one by using below dd commanddd if=/dev/dvd of=/path/to/your/iso/xyz.isoExampledd if=/dev/dvd of=/opt/TestingISO/CentOS-6.2-i386-bin-DVD1.isodd is an excellent disk management tool with which can do many things, in that one is to create ISO images from CD/DVD. "if=/dev/dvd" is my input file from where I am going to take data and write to output file "of=/opt/TestingISO/CentOS-6.2-i386-bin-DVD1.iso".Step3:Now convert your normal iso file to a hybrid ISO.isohybrid /path/to/isofileExample:isohybrid CentOS-6.2-i386-bin-DVD1.isoisohybrid: Warning: more than 1024 cylinders: 3640isohybrid: Not all BIOSes will be able to boot this deviceif you try above command with Linux ISO images like Redhat/Fedora/Centos which are more than 1GB size you may see warning like above one. You can ignore these types of warnings.Note1: Make sure that you did not mount your USB keyNote2: Make sure that you take back up of your data in your USB KeyNote3: It do not matters if the USB pen drive is formated or a brand new oneNote4: Make sure that you are root user before doing below stepNote5: Make sure that you selected right USB device.Note6: If you see below command, We given of=/dev/sdb it is because dd command expects device not a partition.Step4:Now create a bootable USB stick by using following commanddd if=/path/to/iso of=/dev/sdxExample:dd if=CentOS-6.2-i386-bin-DVD1.iso of=/dev/sdbOutput:7454720+0 records in7454720+0 records out3816816640 bytes (3.8 GB) copied, 2168.5 s, 1.8 MB/sOnce created we can insert this pendrive into other machine where you want to install Linux OS.Step5:Change BIOS settings to accept USB drive as bootable device as shown in below image. Select USB device to boot and from there you can start installing any kind of Linux OS as most of the Linux distributions support syslinux.Still have queries?We did a video tutorial for you on how to create USB bootable disk for Fedora Linux OS.