Hi all. This thread will be expanded in the near future. I am on mobile right now, typing is hell. Installation: - Download Sophos XG "Software ISO for Intel hardware" - Download RUFUS - Download GParted ISO or any other disk management liveCD - Prepare 2x USB drives with size of 32GB or less!! > 1 gets GParted with FAT32 set as both options, I used additional partitions for compatibility (use RUFUS), copy in DD mode > 1 gets Sophos XG ISO with FAT32 and 8kb sector size maximum (or less), copy in DD mode, too! - run DISKPART after you copied the Sophos USB > list disk > select disk # (number of USB drive with Sophos on it) > list partition (1 is listed with 2048kb size) > select partition # (number of 2048kb partition) > active -if the harddisk of your intended Sophos appliance is NOT clean, boot it into GParted now and clean any partition OR do a secure erase if SSD. Disk MUST be 100% clean!! - boot from Sophos USB and install OS - reboot and try to boot from OS disk - (if it fails) reboot and run GParted again > select the OS disk > select the partition with the "/BOOT" description, right click and choose "markers" (iirc) > click checkbox at "boot" > OK and apply changes - reboot and boot from OS disk - "first run" will happen The internet is FULL of error reports and people who wasted days if not weeks just to get it to (re-)boot. P. S.: I heard some users have problems with booting first time. System hangs after message "Booting xxxxxxx". Just restart up to 3 times, it is a RAID issue. Sounds stupid but works. Maybe this helps some restless souls.