I know I am probably making a duplicate. But there are so many duplicates already that finding an answer to my specific questions will take hours. If not more. I tried.
So I succeeded in the dual boot. I have a ASUS FX504GM gaming laptop. Windows is on an NVME & the HDD now has DebianTesting.
My question.. did any of this at all effect the EFI partition of Windows NVME? I ask this because when I used to install grub on my old PC which had MBR disks and Legacy BIOS it would ask me which disk I wanted to install grub to.. /dev/sda or /dev/sdb. Idealy I would keep Windows in one disk. And install grub to the sdb that way I would be able to retain both Windows Boot Loader an grub on separate disks. This time .. grub did not ask which partition to INSTALL itself to. Now when I go into my UEFI setup (F2 at start) I see THREE boot option. Two of which are the Debian on disk ST1000LXSJS (Seagate Firecuda) and Windows bootloader on the NVME.
-Why are there two debian boot options?
-How does the EFI partition created on the Debian HDD work?
-Did grub install to two places?
Now here's the funny part.
I messed up the kernel updates and I am reinstalling Debian. I deleted the EFI and root partition on the HDD and my UEFI still shows the boot options.
So did grub add an entry somewhere in the NVME's efi partition?