I was installing Kubuntu on a system that already had Windows. At the end of the process, I get a grub install error, and when I reboot I I can load neither Linux nor Windows anymore.
The machine is a 2016 model of Lenovo Thinkpad T460. It had Windows 10 pre-installed. From the system info within Windows, I could see that the disk drive uses MBR and that the bios mode was legacy. I put the Kubuntu .iso file onto a USB, but couldn't boot into it. I had to change the BIOS settings so that the boot mode was not "legacy", but something like "try UEFI first". After that, I was able to boot from the USB.
Once started, the installation process runs smoothly, I manually set up the partitions, and leave grub to install in the default location (/dev/sda: that's where the drive is). Later in the process, I get the error that grub-install has failed, and the installation process aborts. When I reboot, I discover I'm no longer able to boot anything from the disk drive, and changing the BIOS options between legacy and UEFI booting makes no difference.
Then I run the installation process again, this time telling grub to install in an EFI partition at /dev/sda9. Grub fails again: the syslog has a line saying grub had an "Internal error" and then another line saying that grub "failed to register the EFI boot entry: Operation not permitted". So, another failure: after restarting the system, I still can't boot either Linux or Windows.
I imagine that grub and the BIOS have different perceptions of how the disk is set up and how booting is supposed to work. But how do I get them to agree?
The machine is a 2016 model of Lenovo Thinkpad T460. It had Windows 10 pre-installed. From the system info within Windows, I could see that the disk drive uses MBR and that the bios mode was legacy. I put the Kubuntu .iso file onto a USB, but couldn't boot into it. I had to change the BIOS settings so that the boot mode was not "legacy", but something like "try UEFI first". After that, I was able to boot from the USB.
Once started, the installation process runs smoothly, I manually set up the partitions, and leave grub to install in the default location (/dev/sda: that's where the drive is). Later in the process, I get the error that grub-install has failed, and the installation process aborts. When I reboot, I discover I'm no longer able to boot anything from the disk drive, and changing the BIOS options between legacy and UEFI booting makes no difference.
Then I run the installation process again, this time telling grub to install in an EFI partition at /dev/sda9. Grub fails again: the syslog has a line saying grub had an "Internal error" and then another line saying that grub "failed to register the EFI boot entry: Operation not permitted". So, another failure: after restarting the system, I still can't boot either Linux or Windows.
I imagine that grub and the BIOS have different perceptions of how the disk is set up and how booting is supposed to work. But how do I get them to agree?