If you are looking for the Generic SL install images they are located in the SL directory. If you are looking for the full iso images for SL they are located at ftp://ftp.scientificlinux.org/linux/scientific/44/iso/i386/ If you are looking for the Fermi network install images they are located in the SLF directory. All you need for a on site install is the boot.iso file. If you are looking for the full iso images they are located at ftp://ftp.scientificlinux.org/linux/scientific/44/i386/sites/Fermi/iso/