Next copy over the contents of the boot.img.gz into a directory on your newly formatted USB flash drive; # gunzip boot.img.gz; mkdir /mnt/loopback; mount -o loop boot.img /mnt/loopback; # mkdir /mnt/usb; mount /dev/sdz4 /mnt/usb; mkdir /mnt/usb/debian_installer; # cp -r /mnt/loopback/* /mnt/usb/debian_installer # cp debian-XXX-netinstall.iso /mnt/usb # umount /mnt/usb; umount /mnt/loopbackInstall