I dun goofed. I thought my Windows was booting using UEFI, and I installed Ubuntu using UEFI. But now I think my Windows was booting using MBR, and GRUB can’t detect it.
I’m confident the disk is MBR:
> sudo gdisk -l /dev/sdb GPT fdisk (gdisk) version 1.0.3 Partition table scan: MBR: MBR only BSD: not present APM: not present GPT: not present
and that I’m booting via UEFI:
> ls /sys/firmware/efi/ config_table fw_platform_size runtime systab efivars fw_vendor runtime-map vars
How can I fix my GRUB so that it boots using MBR instead of UEFI?
Neither gave me a GRUB menu with Windows listed.