Unable to boot without install media

I am going to preface this by saying I am not new to Linux, I have been using it since before the kernel was even v1.0… but I am by no means an expert, and I am kind of stumped here.

I have what should be a pretty simple issue, grub will not load… The BIOS just does not see a bootable partition or bootable MBR entry.

I am using a an HP Elitebook 8560p, it’s older but decent specs… i5 2nd gen, 8GB RAM, Radeon graphics, and the system is BIOS based but can support basic UEFI (it is disabled by default). I have all UEFI and secure boot settings off, and boot order is optical drive bay, USB device, hard drive, and network boot in that order.

This is a single OS system, no dual boot… starting with a blank hard drive. I can boot the install USB and install the operating system just fine using all the default settings, but if I remove the install media it won’t boot, the BIOS just skips the hard drive and goes right to a Network Boot. If I boot to the install media and then select “Boot from Hard Drive”, the grub menu loads and I can start openSUSE and get to the Plasma login screen and everything in the OS works like normal.

I have tried running YasT and going to Bootloader and verifying the settings are Boot from Master Boot Record and tick Write Generic Boot Code to MBR, it writes fine, updated initrd, and seems to have no issues… but on a reboot it still won’t boot, unless I put in the install media and boot to that and select boot hard drive again.

I can wipe the drive and install Mint, Manjaro, and Fedora, and they all boot fine without the install media.

I am sure this is something simple… any idea what I am missing?

I did a reinstall, this time not accepting defaults in the installer, but reusing the partitioning from a different distro which used DOS partitioning instead of GPT, and everything works.

I guess I don’t really need any assistance, but it would be nice to know why the installer failed using it’s default settings.

Possibly, your BIOS does not understand booting from the MBR of a GPT disk.