How to create a bootable USB key

 

I will assume your USB device is at /dev/sdb
Please backup all your data in your USB key. Because all the data will be deleted.
1) Insert your USB key to your computer which run Linux OS.
Umount the USB partition if linux automatically mounts your USB partition.
2) If your USB device is /dev/sdb, Run the following command to format your USB as one FAT parition
mkdosfs -I /dev/sdbMount the one FAT parition / USB to your Linux OS
3) Copy all the contents under /cdrom/isolinux to your USB partition. eg:
cp -r /cdrom/isolinux/* /dev/sdb/In your USB partition, rename isolinux.cfg to syslinux.cfg. eg:
mv isolinux.cfg syslinux.cfg  
4) Umount your USB partition. eg:
umount /dev/sdbRun the following command to make the USB bootable. eg:
syslinux /dev/sdb

Note: syslinux in some distrabuted linux version will do the all steps to make a bootable usb disk. (so under these linux os, we just run syslinux /dev/sdb) Bad point is that ,u can't modify the boot messages and boot lables that u want urself.