Copied Debian Stretch netinst based on the instructions of Debian USB installation
- netinst ISO from: https://www.debian.org/devel/debian-installer/
- boot.img.gz from: http://ftp.ca.debian.org/debian/dists/testing/main/installer-amd64/current/images/hd-media/
Boot to bios: F12
- had to disable UEFI and SecureBoot so that the USB disk (with Debian Stretch) is detected.
Used a "USB to ethernet" dongle in order to get network access (wifi wasn't automatically detected).
Installed Debian Stretch without any issues. (didn't even have to switch the disk to AHCI in the BIOS).
Post-install, to fix wifi, I installed firmware-brcm80211 from non-free, and rebooted.