I received an HP Elitebook Folio 9470m with Ubuntu Bionic Beaver installed on it. I installed the latest Ubuntu. After reinstalling the laptop and rebooting, the BIOS refused to boot: PXE-E61 Media Failure Check Cable - PXE-M0F Boot Device not Found Hard Disk Error 3F0. The harddrive is ok (tested with the BIOS itself), but the password of the BIOS is lost!
I observed that when a Live-usb_stick is present at power-up, that the computer is automatically booting from that stick! The idea is now to use a small usb-stick (4G) with a bootloader on it. The computer will call the bootloader (as it calls the live-usb-stick). The bootloader must then jump to the installed LM-partition on the hard drive. In this way the computer can be used again. Any ideas how to create such a bootloader?
Method 2
If you want a USB that just boots to GRUB see: https://askubuntu.com/a/1269476/43926. the download, https://phillw.net/isos/linux-tools/uefi-n-bios/dd_grub-boot-template-for-uefi-n-bios.img.xz will produce a USB that only boots to GRUB, There is no OS. It is easy to use it to boot ISO's, hard drives, etc.
Boot a Partition on a Hard Drive from an USB stick
I do this on my office computer because I don't want to mess up it's Windows boot loader.
Step by Step
Create a Full install USB similar to https://askubuntu.com/a/1403793/43926.
Use Windows Disk Management to create a partition the size you want on the hard drive, (~50Gb).
Boot a Live USB and use GParted to copy the Full Install's / partition to the new hard drive partition.
Boot the Full Install USB and run
sudo update-grub
.The next time you boot the Full Install USB, you will be given the choice to boot Windows or the new Ubuntu partition.
I have not tried this with 22.10, 23.04 or 23.10 yet.
Since you are already running Ubuntu 23.10 on the hard drive, and not Windows, the procedure should be similar.
I don't think that you can update-grub on a live USB.