Thanks for the assistance, I had the correct ISO but I was using the wrong EFI boot manager options. Instead of entering the EFI Shell I went to "Boot from a file", then selected the appropriate "REMOVABLE MEDIA" option. Hey presto, the Debian installer appeared! Jeff Beranek Visualisation Solutions SGI Professional Services, UK +44 (0)161 8342395 (direct) +44 (0)7710 581754 (mobile)