Hi All, I am trying to make a customer ISO. When I run this command: mkisofs -o $DESTINATION_FILE -b isolinux/isolinux.bin -c boot.cat \ -no-emul-boot -boot-info-table \ -V "$NAME" -boot-load-size 4 -boot-info-table -R -J -v -T \ -eltorito-alt-boot -e images/efiboot.img \ $DESTINATION_DIR it tells me: Size of boot image is 4 sectors -> No emulation Size of boot image is 17408 sectors -> genisoimage: Error - boot image 'images/efiboot.img' has not an allowable size. This is the exact same file that is on the Everything ISO image. What am I missing ? I also want to make the ISO boot with UEFI. I think I have the right parameters but getting this error. Thoughts? Thanks, Jerry