How to repair dual boot via grub rescue

If a windows update destroyed your normal grub startup and you are landing in grub rescue you can quite easily restore the grub menu and repair your linux windows dual boot setup.

Following steps from today's google AI search summary worked for me:

Manual Boot Steps from GRUB Rescue

If you are stuck at the grub rescue> prompt, follow these steps to load your system:

1. List Partitions: Type ls to see available partitions (e.g., (hd0), (hd0,gpt1), (hd0,gpt2)).

   ls
   

2. Find Root Partition: Search for the partition containing /boot/grub. Type ls (hdX,gptY)/ for each partition until you see boot/, etc/, or home/. Example:

   ls (hd0,gpt2)/
   

3. Set Root and Prefix: Set the variables to the partition found in step 2.

   set root=(hd0,gpt2)
   set prefix=(hd0,gpt2)/boot/grub
   

4. Load Normal Module: Switch to the normal boot mode.

   insmod normal
   normal
   

5. Boot System: The standard GRUB menu should appear, allowing you to select your linux kernel.

Permanent Fix (once inside linux)

Once you have successfully booted into your linux, you must reinstall GRUB to fix the issue permanently:

1. Open a terminal.

2. Run the following commands to reinstall and update GRUB (replace /dev/sda with your actual disk, e.g., nvme0n1):

   # sudo grub-install /dev/sda
   sudo grub-install /dev/nvme0n1
   sudo update-grub