How do I Repair grub after installing windows 11?

[sproid]

Hi, long story short I decided to dual boot with Windows after years with Linux only use. I need help clarifying the steps I should take to fix the booting process. After formatting an extra hdd, the mbr was unrecoverable. So I reinstalled Windows but now I have to manually select the drive to boot into Linux. I found a post that recommended to reinstall grub and updated it but on that post both OSes are on the same drive and EFI is not mentioned.
This is how the partitions looks like:

/dev/sda       dos                                                  
/dev/sda1      dos    0x83                                 ext4     Linux
/dev/sda2      dos    0x83                                 ext4     Linux
/dev/sr0                                                            
/dev/nvme0n1   dos                                                  
/dev/nvme0n1p1 dos    0x83                                 ext4     Linux
/dev/nvme1n1   gpt                                                  
/dev/nvme1n1p1 gpt    c12a7328-f81f-11d2-ba4b-00a0c93ec93f vfat     EFI System
/dev/nvme1n1p2 gpt    e3c9e316-0b5c-4db8-817d-f92df00215aa          Microsoft reserved
/dev/nvme1n1p3 gpt    ebd0a0a2-b9e5-4433-87c0-68b6b72699ck ntfs     Microsoft basic data
/dev/nvme1n1p4 gpt    de94bba4-06d1-4d40-a16a-bfd50179d6ae ntfs     Windows recovery environment

Should I try this:

sudo grub-install --force --target=i386-pc --recheck --boot-directory=/boot /dev/nvme0n1

sudo update-grub

or

root # grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=manjaro --recheck

root # grub-mkconfig -o /boot/grub/grub.cfg

I don’t want to screw up due to not considering EFI.

[Aragorn]

@sproid

root # grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=manjaro --recheck

root # grub-mkconfig -o /boot/grub/grub.cfg

This.

[Mirdarthos]

[root tip] [How To] Dual boot Manjaro and Windows

Difficulty: ★★☆☆☆ Dual boot - Step by Step Target systems Firmware Checklist Windows preparation Manjaro installation Revisions Target systems UEFI Computers with preinstalled Windows (Windows 10) is computers using UEFI firmware. This guide is a generic guide targeted at UEFI installations. However some of the guide does apply even if you are using a BIOS/MBR setup. If you are using a BIOS/MBR (DOS) partition schema watch out for this Skip if using BIOS/MBR To ensure a …

[BG405]

The problem I see here is the Linux partitions being DOS and the Windows ones being GPT. That rules out UEFI/GPT for the Linux installation and not sure if GRUB can handle such a hybrid setup.

[Wollie]

@sproid

I need help clarifying the steps I should take to fix the booting process.

First, you need to clarify if you understand how to have a dual boot installation. Have a look here:

[root tip] [How To] Dual boot Manjaro and Windows

Difficulty: ★★☆☆☆ Dual boot - Step by Step Target systems Firmware Checklist Windows preparation Manjaro installation Revisions Target systems UEFI Computers with preinstalled Windows (Windows 10) is computers using UEFI firmware. This guide is a generic guide targeted at UEFI installations. However some of the guide does apply even if you are using a BIOS/MBR setup. If you are using a BIOS/MBR (DOS) partition schema watch out for this Skip if using BIOS/MBR To ensure a …

@sproid

After formatting an extra hdd, the mbr was unrecoverable.

The MBR of what disk?

@sproid

So I reinstalled Windows but now I have to manually select the drive to boot into Linux.

That’s a good indication Windoze and Linux have been installed in different modes, your Windowze looks to be installed in UEFI mode, your Linux seems to be installed in BIOS mode. A boot of both systems from grub menu is impossible, both OS must be installed in the same mode. There are two options:

a) Keep changing OS via firmware boot
b) Reinstall one system in the mode of the other system

[sproid]

You may be right. In troubleshooting my gpu I installed Windoze and dual boot with other distros but got tired of it, resulting in this problem. Now I need to learn how to reinstall Manjaro as gpt.

The MBR of what disk?

nvme1n1p1 is where I installed Windows. But after reformatting /sda (HDD) to be used in Linux I deleted the MBR without realizing the consequences.

[Wollie]

@sproid

Now I need to learn how to reinstall Manjaro as gpt.

Simple boot the live ISO (prepared on an USB stick) in UEFI mode from your firmware by selecting the corresponding entry. Then the installer Calamares will perform the installation in UEFI mode as well. The partitions you want to use could be prepared upfront with Gparted started from the live ISO as well.