i've spent the last day banging my head against this one and I have no idea why it just simply won't work as documented. My source system is a Sun Ultra 20 workstations running Ubuntu 7.x and my target system is a Dell Inspiron XPS Gen 2 Laptop. I am trying to to create a bootable USB Key from the VMware ESXi 3 ISO, which is an ISOLINUX bootable PROBLEM: I have a usb key (256MB) formatted FAT16 with the first and only partition marked bootable. I've mounted the ISO and /dev/XXX1 I've copied the contents of the ISO to /dev/XXX1 via mount points I've renamed isolinux.cfg to syslinux.cfg on /dev/XXX1 I've run syslinux /dev/XXX1 followed by cat mbr.bin > /dev/XXX The target system, which recognizes that there is a USB device attached on boot and tries to boot from it, does one of two things: just hangs with a cursor in the top left corner or reports a boot failure. SOLUTION: following the same steps except that instead of doing cat mbr.bin > /dev/XXX as described I executed dd if=mbr.bin of=/dev/XXX the usb key is now bootable and the image loads as expected. Has anyone else seen this behaviour? Have i done something wrong in trying to follow the documented process?